"ID","Description","Published","Solved By","Solve Status"
1,"Multiples of 3 or 5",1002301200,994767,1
2,"Even Fibonacci Numbers",1003510800,793361,1
3,"Largest Prime Factor",1004724000,571429,1
4,"Largest Palindrome Product",1005933600,505594,1
5,"Smallest Multiple",1007143200,508489,1
6,"Sum Square Difference",1008352800,511778,1
7,"10001st Prime",1009562400,438054,1
8,"Largest Product in a Series",1010772000,367372,1
9,"Special Pythagorean Triplet",1011981600,372417,1
10,"Summation of Primes",1013191200,341713,1
11,"Largest Product in a Grid",1014400800,245684,1
12,"Highly Divisible Triangular Number",1015610400,232214,1
13,"Large Sum",1016820000,237513,1
14,"Longest Collatz Sequence",1018026000,237924,1
15,"Lattice Paths",1019235600,196653,1
16,"Power Digit Sum",1020445200,240163,1
17,"Number Letter Counts",1021654800,159820,1
18,"Maximum Path Sum I",1022864400,153051,1
19,"Counting Sundays",1024074000,142124,1
20,"Factorial Digit Sum",1024678800,207933,1
21,"Amicable Numbers",1025888400,154318,1
22,"Names Scores",1027098000,141912,1
23,"Non-Abundant Sums",1028307600,110631,1
24,"Lexicographic Permutations",1029517200,121363,1
25,"$1000$-digit Fibonacci Number",1030726800,163651,1
26,"Reciprocal Cycles",1031936400,89472,1
27,"Quadratic Primes",1033146000,92909,1
28,"Number Spiral Diagonals",1034355600,114027,1
29,"Distinct Powers",1035565200,111741,1
30,"Digit Fifth Powers",1036778400,116264,1
31,"Coin Sums",1037988000,90577,1
32,"Pandigital Products",1039197600,75981,1
33,"Digit Cancelling Fractions",1040407200,76299,1
34,"Digit Factorials",1041616800,99789,1
35,"Circular Primes",1042826400,89860,1
36,"Double-base Palindromes",1044036000,94020,1
37,"Truncatable Primes",1045245600,78224,1
38,"Pandigital Multiples",1046455200,67182,1
39,"Integer Right Triangles",1047664800,77780,1
40,"Champernowne's Constant",1048874400,84911,1
41,"Pandigital Prime",1050080400,72566,1
42,"Coded Triangle Numbers",1051290000,78908,1
43,"Sub-string Divisibility",1052499600,63914,1
44,"Pentagon Numbers",1053709200,62546,1
45,"Triangular, Pentagonal, and Hexagonal",1054918800,75260,1
46,"Goldbach's Other Conjecture",1056128400,65743,1
47,"Distinct Primes Factors",1057338000,61941,1
48,"Self Powers",1058547600,118050,1
49,"Prime Permutations",1059757200,61805,1
50,"Consecutive Prime Sum",1060966800,66623,1
51,"Prime Digit Replacements",1062176400,36750,0
52,"Permuted Multiples",1063386000,69252,1
53,"Combinatoric Selections",1064595600,62593,1
54,"Poker Hands",1065805200,38781,0
55,"Lychrel Numbers",1067014800,57249,1
56,"Powerful Digit Sum",1068228000,61846,1
57,"Square Root Convergents",1069437600,44608,1
58,"Spiral Primes",1070647200,43037,1
59,"XOR Decryption",1071856800,43998,0
60,"Prime Pair Sets",1073066400,29060,0
61,"Cyclical Figurate Numbers",1074276000,27595,0
62,"Cubic Permutations",1075485600,33984,0
63,"Powerful Digit Counts",1076695200,46091,0
64,"Odd Period Square Roots",1077904800,23973,0
65,"Convergents of $e$",1079114400,32149,0
66,"Diophantine Equation",1080324000,21380,0
67,"Maximum Path Sum II",1081530000,100857,0
68,"Magic 5-gon Ring",1082739600,22474,0
69,"Totient Maximum",1083949200,37428,0
70,"Totient Permutation",1085158800,24145,0
71,"Ordered Fractions",1086368400,31438,0
72,"Counting Fractions",1087578000,24180,0
73,"Counting Fractions in a Range",1088787600,26900,0
74,"Digit Factorial Chains",1089997200,28739,0
75,"Singular Integer Right Triangles",1091206800,19559,0
76,"Counting Summations",1092416400,30643,0
77,"Prime Summations",1093626000,20806,0
78,"Coin Partitions",1094835600,18412,1
79,"Passcode Derivation",1095440400,43370,0
80,"Square Root Digital Expansion",1097254800,21434,0
81,"Path Sum: Two Ways",1098464400,36640,0
82,"Path Sum: Three Ways",1099677600,22714,0
83,"Path Sum: Four Ways",1100887200,19641,0
84,"Monopoly Odds",1102096800,13751,0
85,"Counting Rectangles",1103306400,26518,0
86,"Cuboid Route",1105120800,13810,0
87,"Prime Power Triples",1106330400,22477,0
88,"Product-sum Numbers",1107540000,11057,0
89,"Roman Numerals",1108749600,22636,0
90,"Cube Digit Pairs",1109959200,12318,0
91,"Right Triangles with Integer Coordinates",1111168800,16709,0
92,"Square Digit Chains",1112374800,44145,1
93,"Arithmetic Expressions",1113584400,12861,0
94,"Almost Equilateral Triangles",1114794000,13525,0
95,"Amicable Chains",1116003600,15564,0
96,"Su Doku",1117213200,18513,0
97,"Large Non-Mersenne Prime",1118422800,45689,0
98,"Anagramic Squares",1119027600,12396,0
99,"Largest Exponential",1120237200,32642,0
100,"Arranged Probability",1121446800,17673,0
101,"Optimum Polynomial",1122656400,12524,0
102,"Triangle Containment",1123866000,23464,0
103,"Special Subset Sums: Optimum",1125075600,8771,0
104,"Pandigital Fibonacci Ends",1126285200,17336,0
105,"Special Subset Sums: Testing",1127494800,8743,0
106,"Special Subset Sums: Meta-testing",1128704400,6980,1
107,"Minimal Network",1129914000,11828,0
108,"Diophantine Reciprocals I",1131127200,13587,0
109,"Darts",1132336800,8816,0
110,"Diophantine Reciprocals II",1133546400,8739,0
111,"Primes with Runs",1134756000,7855,0
112,"Bouncy Numbers",1135965600,26200,0
113,"Non-bouncy Numbers",1139594400,11879,0
114,"Counting Block Combinations I",1140199200,11645,0
115,"Counting Block Combinations II",1140804000,10636,0
116,"Red, Green or Blue Tiles",1141408800,12964,0
117,"Red, Green, and Blue Tiles",1142013600,11937,0
118,"Pandigital Prime Sets",1143223200,7560,0
119,"Digit Power Sum",1144429200,13216,0
120,"Square Remainders",1145638800,14733,0
121,"Disc Game Prize Fund",1148058000,10427,0
122,"Efficient Exponentiation",1149267600,8443,0
123,"Prime Square Remainders",1150477200,12322,0
124,"Ordered Radicals",1152896400,14580,0
125,"Palindromic Sums",1154710800,14471,0
126,"Cuboid Layers",1155920400,5148,0
127,"abc-hits",1157130000,6755,0
128,"Hexagonal Tile Differences",1159549200,5417,0
129,"Repunit Divisibility",1161968400,6772,0
130,"Composites with Prime Repunit Property",1161968400,6366,0
131,"Prime Cube Partnership",1163181600,7927,0
132,"Large Repunit Factors",1164996000,6817,0
133,"Repunit Nonfactors",1164996000,5955,0
134,"Prime Pair Connection",1166205600,7537,0
135,"Same Differences",1167415200,6895,0
136,"Singleton Difference",1167415200,6139,0
137,"Fibonacci Golden Nuggets",1168624800,5964,0
138,"Special Isosceles Triangles",1169290800,6286,0
139,"Pythagorean Tiles",1169888400,6101,0
140,"Modified Fibonacci Golden Nuggets",1170486000,4702,0
141,"Square Progressive Numbers",1171688400,4277,0
142,"Perfect Square Collection",1172278800,6245,0
143,"Torricelli Triangles",1172869200,2988,0
144,"Laser Beam Reflections ",1173459600,6751,0
145,"Reversible Numbers",1174050000,17679,0
146,"Investigating a Prime Pattern ",1174726800,5461,0
147,"Rectangles in Cross-hatched Grids",1175317200,3288,0
148,"Exploring Pascal's Triangle",1175907600,5540,0
149,"Maximum-sum Subsequence",1176498000,5210,0
150,"Sub-triangle Sums",1176498000,4264,0
151,"A Preference for A5",1177088400,5948,0
152,"Sums of Square Reciprocals",1177678800,2920,0
153,"Investigating Gaussian Integers",1178355600,2839,0
154,"Exploring Pascal's Pyramid",1178946000,2852,0
155,"Counting Capacitor Circuits",1179536400,3872,0
156,"Counting Digits",1180126800,2643,0
157,"Base-10 Diophantine Reciprocal",1180717200,2937,0
158,"Lexicographical Neighbours",1181912400,3916,0
159,"Digital Root Sums of Factorisations",1183208400,3531,0
160,"Factorial Trailing Digits",1189170000,3778,0
161,"Triominoes",1190394000,2309,0
162,"Hexadecimal Numbers",1191618000,5719,0
163,"Cross-hatched Triangles",1192237200,1976,0
164,"Three Consecutive Digital Sum Limit",1192856400,6126,0
165,"Intersections",1193475600,2815,0
166,"Criss Cross",1194094800,4402,0
167,"Investigating Ulam Sequences",1194613200,1846,0
168,"Number Rotations",1195232400,2873,0
169,"Sums of Powers of Two",1195851600,5458,0
170,"Pandigital Concatenating Products",1196470800,2152,0
171,"Square Sum of the Digital Squares",1197090000,3006,0
172,"Few Repeated Digits",1197709200,4074,0
173,"Hollow Square Laminae I",1198328400,9623,0
174,"Hollow Square Laminae II",1198328400,6261,0
175,"Fractions and Sum of Powers of Two",1198846800,1934,0
176,"Common Cathetus Right-angled Triangles",1199466000,2053,0
177,"Integer Angled Quadrilaterals",1200085200,1389,0
178,"Step Numbers",1200704400,3661,0
179,"Consecutive Positive Divisors",1201323600,11881,0
180,"Golden Triplets",1201942800,1714,0
181,"Grouping Two Different Coloured Objects",1202562000,2163,0
182,"RSA Encryption",1203080400,2791,0
183,"Maximum Product of Parts",1203699600,4964,0
184,"Triangles Containing the Origin",1204318800,1784,0
185,"Number Mind",1204938000,3356,0
186,"Connectedness of a Network",1205557200,3059,0
187,"Semiprimes",1206176400,11798,0
188,"Hyperexponentiation",1207314000,6736,0
189,"Tri-colouring a Triangular Grid",1207929600,2218,0
190,"Maximising a Weighted Product",1208552400,4420,0
191,"Prize Strings",1209168000,7502,0
192,"Best Approximations",1209787200,1769,0
193,"Squarefree Numbers",1210420800,3620,0
194,"Coloured Configurations",1211014800,1522,0
195,"$60$-degree Triangle Inscribed Circles",1211547600,1515,0
196,"Prime Triplets",1212166800,2777,0
197,"A Recursively Defined Sequence",1212786000,5201,0
198,"Ambiguous Numbers",1213405200,1222,0
199,"Iterative Circle Packing",1214024400,2101,0
200,"Prime-proof Squbes",1214643600,2569,0
201,"Subsets with a Unique Sum",1215262800,2501,0
202,"Laserbeam",1215262800,2733,0
203,"Squarefree Binomial Coefficients",1220706000,9636,0
204,"Generalised Hamming Numbers",1220706000,7760,0
205,"Dice Game",1220706000,15689,0
206,"Concealed Square",1220706000,25698,0
207,"Integer Partition Equations",1220706000,4984,0
208,"Robot Walks",1221224400,1884,0
209,"Circular Logic",1221843600,2676,0
210,"Obtuse Angled Triangles",1222462800,1820,0
211,"Divisor Square Sum",1223082000,4461,0
212,"Combined Volume of Cuboids",1223701200,1487,0
213,"Flea Circus",1224320400,2498,0
214,"Totient Chains",1224939600,5530,0
215,"Crack-free Walls",1225458000,3901,0
216,"The Primality of $2n^2 - 1$",1226077200,4359,0
217,"Balanced Numbers",1226696400,1620,0
218,"Perfect Right-angled Triangles",1227315600,3202,0
219,"Skew-cost Coding",1227934800,1574,0
220,"Heighway Dragon",1228554000,2304,0
221,"Alexandrian Integers",1229173200,2239,0
222,"Sphere Packing",1229691600,2220,0
223,"Almost Right-angled Triangles I",1230310800,1645,0
224,"Almost Right-angled Triangles II",1230310800,1332,0
225,"Tribonacci Non-divisors",1230310800,4723,0
226,"A Scoop of Blancmange",1230930000,1855,0
227,"The Chase",1231549200,2255,0
228,"Minkowski Sums",1232168400,1421,0
229,"Four Representations Using Squares",1232787600,1569,0
230,"Fibonacci Words",1233406800,3035,0
231,"Prime Factorisation of Binomial Coefficients",1233925200,5766,0
232,"The Race",1234544400,1914,0
233,"Lattice Points on a Circle",1235163600,2486,0
234,"Semidivisible Numbers",1235782800,3435,0
235,"An Arithmetic Geometric Sequence",1236402000,5252,0
236,"Luxury Hampers",1237021200,1011,0
237,"Tours on a $4 \times N$ Playing Board",1237640400,1685,0
238,"Infinite String Tour",1238335200,1036,0
239,"Twenty-two Foolish Primes",1238774400,1934,0
240,"Top Dice",1239397200,2324,0
241,"Perfection Quotients",1240016400,999,0
242,"Odd Triplets",1240635600,1114,0
243,"Resilience",1241254800,10077,0
244,"Sliders",1241874000,1409,0
245,"Coresilience",1242392400,881,0
246,"Tangents to an Ellipse",1243008000,867,0
247,"Squares Under a Hyperbola",1243627200,1571,0
248,"Euler's Totient Function Equals 13!",1244246400,1392,0
249,"Prime Subset Sums",1244865600,2698,0
250,"$250250$",1244865600,3177,0
251,"Cardano Triplets",1245484800,1490,0
252,"Convex Holes",1246104000,904,0
253,"Tidying Up A",1251460800,1107,0
254,"Sums of Digit Factorials",1252080000,1037,0
255,"Rounded Square Roots",1252699200,932,0
256,"Tatami-Free Rooms",1253318400,787,0
257,"Angular Bisectors",1253937600,745,0
258,"A Lagged Fibonacci Sequence",1254556800,1712,0
259,"Reachable Numbers",1255176000,1613,0
260,"Stone Game",1255694400,1407,0
261,"Pivotal Square Sums",1256313600,742,0
262,"Mountain Range",1256936400,771,0
263,"An Engineers' Dream Come True",1257555600,1119,0
264,"Triangle Centres",1258174800,611,0
265,"Binary Circles",1258794000,4442,0
266,"Pseudo Square Root",1259413200,1810,0
267,"Billionaire",1259931600,3615,0
268,"At Least Four Distinct Prime Factors Less Than 100",1260550800,1553,0
269,"Polynomials with at Least One Integer Root",1261213200,747,0
270,"Cutting Squares",1261789200,682,0
271,"Modular Cubes, Part 1",1262408400,2538,0
272,"Modular Cubes, Part 2",1262408400,1058,0
273,"Sum of Squares",1263042000,1473,0
274,"Divisibility Multipliers",1263560400,1510,0
275,"Balanced Sculptures",1264179600,654,0
276,"Primitive Triangles",1264798800,1163,0
277,"A Modified Collatz Sequence",1265418000,3418,0
278,"Linear Combinations of Semiprimes",1266037200,1108,0
279,"Triangles with Integral Sides and an Integral Angle ",1266656400,797,0
280,"Ant and Seeds",1267275600,1120,0
281,"Pizza Toppings",1267794000,1048,0
282,"The Ackermann Function",1268413200,1093,0
283,"Integer Sided Triangles with Integral Area/perimeter Ratio",1269032400,675,0
284,"Steady Squares",1269651600,1344,0
285,"Pythagorean Odds",1270267200,1302,0
286,"Scoring Probabilities",1270267200,2270,0
287,"Quadtree Encoding (a Simple Compression Algorithm)",1270886400,1544,0
288,"An Enormous Factorial",1271505600,1769,0
289,"Eulerian Cycles",1272024000,529,0
290,"Digital Signature",1272643200,1043,0
291,"Panaitopol Primes",1273262400,1541,0
292,"Pythagorean Polygons",1273881600,609,0
293,"Pseudo-Fortunate Numbers",1274500800,3154,0
294,"Sum of Digits - Experience #23",1275120000,986,0
295,"Lenticular Holes",1275739200,490,0
296,"Angular Bisector and Tangent",1276257600,636,0
297,"Zeckendorf Representation",1276876800,2934,0
298,"Selective Amnesia",1277496000,715,0
299,"Three Similar Triangles",1278115200,664,0
300,"Protein Folding",1283601600,1185,0
301,"Nim",1284217200,6887,0
302,"Strong Achilles Numbers",1284832800,797,0
303,"Multiples with Small Digits",1285448400,3841,0
304,"Primonacci",1286064000,2335,0
305,"Reflexive Position",1286679600,647,0
306,"Paper-strip Game",1287295200,1298,0
307,"Chip Defects",1287910800,1759,0
308,"An Amazing Prime-generating Automaton",1288440000,821,0
309,"Integer Ladders",1289059200,878,0
310,"Nim Square",1289674800,1239,0
311,"Biclinic Integral Quadrilaterals",1290290400,459,0
312,"Cyclic Paths on Sierpiński Graphs",1290906000,898,0
313,"Sliding Game",1291521600,1712,0
314,"The Mouse on the Moon",1292137200,553,0
315,"Digital Root Clocks",1292752800,3590,0
316,"Numbers in Decimal Expansions",1293282000,709,0
317,"Firecracker",1293897600,2843,0
318,"2011 Nines",1293897600,994,0
319,"Bounded Sequences",1294513200,429,0
320,"Factorials Divisible by a Huge Integer",1295128800,931,0
321,"Swapping Counters",1295744400,1836,0
322,"Binomial Coefficients Divisible by 10",1296360000,493,0
323,"Bitwise-OR Operations on Random Integers",1296975600,4125,0
324,"Building a Tower",1297591200,749,0
325,"Stone Game II",1298120400,652,0
326,"Modulo Summations",1298736000,566,0
327,"Rooms of Doom",1299351600,1198,0
328,"Lowest-cost Search",1299967200,473,0
329,"Prime Frog",1300582800,2665,0
330,"Euler's Number",1301198400,569,0
331,"Cross Flips",1301814000,447,0
332,"Spherical Triangles",1302426000,654,0
333,"Special Partitions",1302955200,1325,0
334,"Spilling the Beans",1303570800,508,0
335,"Gathering the Beans",1303570800,547,0
336,"Maximix Arrangements",1304186400,2199,0
337,"Totient Stairstep Sequences",1304802000,560,0
338,"Cutting Rectangular Grid Paper",1305417600,351,0
339,"Peredur Fab Efrawg",1306033200,600,0
340,"Crazy Function",1306648800,1182,0
341,"Golomb's Self-describing Sequence",1307264400,990,0
342,"The Totient of a Square Is a Cube",1307793600,855,0
343,"Fractional Sequences",1308409200,1490,0
344,"Silver Dollar Game",1309024800,348,0
345,"Matrix Sum",1315062000,6043,0
346,"Strong Repunits",1315062000,4615,0
347,"Largest Integer Divisible by Two Primes",1315062000,4868,0
348,"Sum of a Square and a Cube",1315062000,3238,0
349,"Langton's Ant",1315062000,2041,0
350,"Constraining the Least Greatest and the Greatest Least",1315677600,502,0
351,"Hexagonal Orchards",1316293200,2722,0
352,"Blood Tests",1317513600,647,0
353,"Risky Moon",1318129200,521,0
354,"Distances in a Bee's Honeycomb ",1318744800,475,0
355,"Maximal Coprime Subset",1319360400,566,0
356,"Largest Roots of Cubic Polynomials",1319889600,635,0
357,"Prime Generating Integers",1320508800,8647,0
358,"Cyclic Numbers",1321124400,1713,0
359,"Hilbert's New Hotel",1321740000,1617,0
360,"Scary Sphere",1322355600,620,0
361,"Subsequence of Thue-Morse Sequence",1322971200,328,0
362,"Squarefree Factors",1323586800,504,0
363,"Bézier Curves",1324202400,1189,0
364,"Comfortable Distance",1324731600,749,0
365,"A Huge Binomial Coefficient",1325347200,1358,0
366,"Stone Game III",1325962800,729,0
367,"Bozo Sort",1326578400,549,0
368,"A Kempner-like Series",1327194000,579,0
369,"Badugi",1327809600,492,0
370,"Geometric Triangles",1328425200,564,0
371,"Licence Plates",1329040800,1737,0
372,"Pencils of Rays",1329570000,428,0
373,"Circumscribed Circles",1330185600,365,0
374,"Maximum Integer Partition Product",1330801200,724,0
375,"Minimum of Subsequences",1331416800,945,0
376,"Nontransitive Sets of Dice",1332032400,300,0
377,"Sum of Digits - Experience #13",1332648000,772,0
378,"Triangle Triples",1333260000,932,0
379,"Least Common Multiple Count",1333879200,554,0
380,"Amazing Mazes!",1334408400,542,0
381,"$(\text{prime}-k)$ Factorial",1335024000,4538,0
382,"Generating Polygons",1335639600,357,0
383,"Divisibility Comparison Between Factorials",1336255200,504,0
384,"Rudin-Shapiro Sequence",1336870800,352,0
385,"Ellipses Inside Triangles",1337486400,302,0
386,"Maximum Length of an Antichain",1338102000,792,0
387,"Harshad Numbers",1338717600,4950,0
388,"Distinct Lines",1339246800,625,0
389,"Platonic Dice",1339862400,1635,0
390,"Triangles with Non Rational Sides and Integral Area",1340478000,597,0
391,"Hopping Game",1341093600,285,0
392,"Enmeshed Unit Circle",1346504400,832,0
393,"Migrating Ants",1347120000,814,0
394,"Eating Pie",1347735600,568,0
395,"Pythagorean Tree",1348351200,733,0
396,"Weak Goodstein Sequence",1348966800,701,0
397,"Triangle on Parabola",1349582400,287,0
398,"Cutting Rope",1350198000,404,0
399,"Squarefree Fibonacci Numbers",1350813600,608,0
400,"Fibonacci Tree Game",1351342800,499,0
401,"Sum of Squares of Divisors",1352563200,2758,0
402,"Integer-valued Polynomials",1353178800,437,0
403,"Lattice Points Enclosed by Parabola and Line",1353794400,379,0
404,"Crisscross Ellipses",1354410000,341,0
405,"A Rectangular Tiling",1355025600,652,0
406,"Guessing Game",1355641200,395,0
407,"Idempotents",1356256800,2618,0
408,"Admissible Paths Through a Grid",1356786000,607,0
409,"Nim Extreme",1357401600,475,0
410,"Circle and Tangent Line",1358017200,291,0
411,"Uphill Paths",1358632800,704,0
412,"Gnomon Numbering",1359248400,525,0
413,"One-child Numbers",1359864000,414,0
414,"Kaprekar Constant",1360479600,305,0
415,"Titanic Sets",1361095200,337,0
416,"A Frog's Trip",1361624400,308,0
417,"Reciprocal Cycles II",1362240000,942,0
418,"Factorisation Triples",1362855600,732,0
419,"Look and Say Sequence",1363471200,518,0
420,"$2 \times 2$ Positive Integer Matrix",1364086800,467,0
421,"Prime Factors of $n^{15}+1$",1364698800,704,0
422,"Sequence of Points on a Hyperbola",1365314400,299,0
423,"Consecutive Die Throws",1365930000,519,0
424,"Kakuro",1366459200,436,0
425,"Prime Connection",1367074800,1561,0
426,"Box-Ball System",1367690400,267,0
427,"$n$-sequences",1368306000,338,0
428,"Necklace of Circles",1368921600,265,0
429,"Sum of Squares of Unitary Divisors",1369537200,2689,0
430,"Range Flips",1370152800,908,0
431,"Square Space Silo",1370768400,651,0
432,"Totient Sum",1371297600,525,0
433,"Steps in Euclid's Algorithm",1371913200,491,0
434,"Rigid Graphs",1372528800,352,0
435,"Polynomials of Fibonacci Numbers",1378566000,1191,0
436,"Unfair Wager",1379181600,483,0
437,"Fibonacci Primitive Roots",1379797200,848,0
438,"Integer Part of Polynomial Equation's Solutions",1380412800,292,0
439,"Sum of Sum of Divisors",1381028400,414,0
440,"GCD and Tiling",1381644000,407,0
441,"The Inverse Summation of Coprime Couples",1382259600,380,0
442,"Eleven-free Integers",1382788800,415,0
443,"GCD Sequence",1383408000,1211,0
444,"The Roundtable Lottery",1384023600,325,0
445,"Retractions A",1384639200,412,0
446,"Retractions B",1384639200,390,0
447,"Retractions C",1384639200,326,0
448,"Average Least Common Multiple",1385254800,369,0
449,"Chocolate Covered Candy",1386475200,959,0
450,"Hypocycloid and Lattice Points",1387090800,203,0
451,"Modular Inverses",1387706400,1539,0
452,"Long Products",1388235600,616,0
453,"Lattice Quadrilaterals",1388851200,230,0
454,"Diophantine Reciprocals III",1389466800,508,0
455,"Powers with Trailing Digits",1390082400,770,0
456,"Triangles Containing the Origin II",1390698000,424,0
457,"A Polynomial Modulo the Square of a Prime",1391313600,849,0
458,"Permutations of Project",1391929200,980,0
459,"Flipping Game",1392544800,251,0
460,"An Ant on the Move",1393074000,340,0
461,"Almost Pi",1393689600,1285,0
462,"Permutation of 3-smooth Numbers",1394305200,339,0
463,"A Weird Recurrence Relation",1394920800,1166,0
464,"Möbius Function and Intervals",1395536400,346,0
465,"Polar Polygons",1396152000,233,0
466,"Distinct Terms in a Multiplication Table",1396764000,345,0
467,"Superinteger",1397379600,469,0
468,"Smooth Divisors of Binomial Coefficients",1397908800,294,0
469,"Empty Chairs",1398524400,792,0
470,"Super Ramvok",1399140000,247,0
471,"Triangle Inscribed in Ellipse",1399755600,231,0
472,"Comfortable Distance II",1400371200,274,0
473,"Phigital Number Base",1400986800,771,0
474,"Last Digits of Divisors",1401602400,441,0
475,"Music Festival",1402218000,470,0
476,"Circle Packing II",1402747200,437,0
477,"Number Sequence Game",1408806000,277,0
478,"Mixtures",1409421600,203,0
479,"Roots on the Rise",1410037200,1375,0
480,"The Last Question",1410652800,613,0
481,"Chef Showdown",1411268400,260,0
482,"The Incenter of a Triangle",1411884000,231,0
483,"Repeated Permutation",1412499600,270,0
484,"Arithmetic Derivative",1413028800,398,0
485,"Maximum Number of Divisors",1413644400,1232,0
486,"Palindrome-containing Strings",1414260000,278,0
487,"Sums of Power Sums",1414879200,689,0
488,"Unbalanced Nim",1415494800,248,0
489,"Common Factors Between Two Sequences",1416110400,267,0
490,"Jumping Frog",1416726000,321,0
491,"Double Pandigital Number Divisible by $11$",1417341600,2277,0
492,"Exploding Sequence",1417870800,379,0
493,"Under the Rainbow",1418486400,5645,0
494,"Collatz Prefix Families",1419102000,229,0
495,"Writing $n$ as the Product of $k$ Distinct Positive Integers",1419717600,323,0
496,"Incenter and Circumcenter of Triangle",1420333200,329,0
497,"Drunken Tower of Hanoi",1420948800,582,0
498,"Remainder of Polynomial Division",1421564400,549,0
499,"St. Petersburg Lottery",1422180000,357,0
500,"Problem 500!!!",1422709200,4285,0
501,"Eight Divisors",1422709200,1463,0
502,"Counting Castles",1423324800,311,0
503,"Compromise or Persist",1423940400,337,0
504,"Square on the Inside",1424556000,3250,0
505,"Bidirectional Recurrence",1425171600,221,0
506,"Clock Sequence",1425787200,921,0
507,"Shortest Lattice Vector",1426402800,228,0
508,"Integers in Base $i-1$",1427018400,248,0
509,"Divisor Nim",1427547600,620,0
510,"Tangent Circles",1428159600,1068,0
511,"Sequences with Nice Divisibility Properties",1428775200,438,0
512,"Sums of Totients of Powers",1429390800,1590,0
513,"Integral Median",1430006400,327,0
514,"Geoboard Shapes",1430622000,228,0
515,"Dissonant Numbers",1431237600,490,0
516,"$5$-smooth Totients",1431853200,1651,0
517,"A Real Recursion",1432382400,482,0
518,"Prime Triples and Geometric Sequences",1432998000,1700,0
519,"Tricoloured Coin Fountains",1433613600,361,0
520,"Simbers",1434229200,437,0
521,"Smallest Prime Factor",1434844800,796,0
522,"Hilbert's Blackout",1435460400,287,0
523,"First Sort I",1441519200,1053,0
524,"First Sort II",1441519200,240,0
525,"Rolling Ellipse",1442134800,524,0
526,"Largest Prime Factors of Consecutive Numbers",1442664000,329,0
527,"Randomized Binary Search",1443279600,778,0
528,"Constrained Sums",1443895200,295,0
529,"$10$-substrings",1444510800,265,0
530,"GCD of Divisors",1445126400,482,0
531,"Chinese Leftovers",1445745600,1212,0
532,"Nanobots on Geodesics",1446361200,322,0
533,"Minimum Values of the Carmichael Function",1446976800,348,0
534,"Weak Queens",1447506000,327,0
535,"Fractal Sequence",1448121600,304,0
536,"Modulo Power Identity ",1448737200,310,0
537,"Counting Tuples",1449352800,668,0
538,"Maximum Quadrilaterals",1449968400,342,0
539,"Odd Elimination",1450584000,874,0
540,"Counting Primitive Pythagorean Triples",1451199600,698,0
541,"Divisibility of Harmonic Number Denominators",1451815200,222,0
542,"Geometric Progression with Maximum Sum",1452344400,242,0
543,"Prime-Sum Numbers",1452960000,733,0
544,"Chromatic Conundrum",1453575600,271,0
545,"Faulhaber's Formulas",1454191200,560,0
546,"The Floor's Revenge",1454806800,247,0
547,"Distance of Random Points Within Hollow Square Laminae",1455422400,243,0
548,"Gozinta Chains",1456038000,657,0
549,"Divisibility of Factorials",1456653600,2887,0
550,"Divisor Game",1457182800,377,0
551,"Sum of Digits Sequence",1457798400,495,0
552,"Chinese Leftovers II",1458414000,465,0
553,"Power Sets of Power Sets",1459029600,223,0
554,"Centaurs on a Chess Board",1459641600,254,0
555,"McCarthy 91 Function",1460257200,738,0
556,"Squarefree Gaussian Integers",1460872800,265,0
557,"Cutting Triangles",1461488400,303,0
558,"Irrational Base",1462017600,267,0
559,"Permuted Matrices",1462633200,202,0
560,"Coprime Nim",1463248800,342,0
561,"Divisor Pairs",1463864400,813,0
562,"Maximal Perimeter",1464480000,201,0
563,"Robot Welders",1465095600,350,0
564,"Maximal Polygons",1465711200,253,0
565,"Divisibility of Sum of Divisors",1466326800,658,0
566,"Cake Icing Puzzle",1466856000,192,0
567,"Reciprocal Games I",1472914800,314,0
568,"Reciprocal Games II",1472914800,307,0
569,"Prime Mountain Range",1473530400,417,0
570,"Snowflakes",1474146000,287,0
571,"Super Pandigital Numbers",1474761600,1162,0
572,"Idempotent Matrices",1475377200,358,0
573,"Unfair Race",1475992800,219,0
574,"Verifying Primes",1476608400,280,0
575,"Wandering Robots",1477137600,620,0
576,"Irrational Jumps",1477753200,247,0
577,"Counting Hexagons",1478977200,1661,0
578,"Integers with Decreasing Prime Powers",1479592800,252,0
579,"Lattice Points in Lattice Cubes",1480208400,177,0
580,"Squarefree Hilbert Numbers",1480824000,269,0
581,"$47$-smooth Triangular Numbers",1481439600,915,0
582,"Nearly Isosceles $120$ Degree Triangles",1482055200,343,0
583,"Heron Envelopes",1482584400,388,0
584,"Birthday Problem Revisited",1483200000,224,0
585,"Nested Square Roots",1483815600,191,0
586,"Binary Quadratic Form",1484431200,245,0
587,"Concave Triangle",1485046800,3310,0
588,"Quintinomial Coefficients",1485662400,463,0
589,"Poohsticks Marathon",1486278000,215,0
590,"Sets with a Given Least Common Multiple",1486893600,276,0
591,"Best Approximations by Quadratic Integers",1487422800,204,0
592,"Factorial Trailing Digits 2",1488038400,303,0
593,"Fleeting Medians",1488654000,567,0
594,"Rhombus Tilings",1489269600,201,0
595,"Incremental Random Sort",1489885200,659,0
596,"Number of Lattice Points in a Hyperball",1490497200,381,0
597,"Torpids",1491112800,183,0
598,"Split Divisibilities",1491728400,512,0
599,"Distinct Colourings of a Rubik's Cube",1492257600,325,0
600,"Integer Sided Equiangular Hexagons",1492873200,645,0
601,"Divisibility Streaks",1493488800,2162,0
602,"Product of Head Counts",1494104400,526,0
603,"Substring Sums of Prime Concatenations",1494720000,455,0
604,"Convex Path in Square",1495335600,533,0
605,"Pairwise Coin-Tossing Game",1495951200,889,0
606,"Gozinta Chains II",1496566800,399,0
607,"Marsh Crossing",1497096000,1788,0
608,"Divisor Sums",1497711600,320,0
609,"$\pi$ Sequences",1504969200,983,0
610,"Roman Numerals II",1506189600,606,0
611,"Hallway of Square Steps",1507410000,351,0
612,"Friend Numbers",1508630400,715,0
613,"Pythagorean Ant",1509854400,1892,0
614,"Special Partitions 2",1511074800,321,0
615,"The Millionth Number with at Least One Million Prime Factors",1512295200,615,0
616,"Creative Numbers",1513429200,504,0
617,"Mirror Power Sequence",1514649600,395,0
618,"Numbers with a Given Prime Factor Sum",1515870000,1099,0
619,"Square Subsets",1517090400,422,0
620,"Planetary Gears",1518310800,179,0
621,"Expressing an Integer as the Sum of Triangular Numbers",1519531200,583,0
622,"Riffle Shuffles",1520751600,1829,0
623,"Lambda Count",1521968400,331,0
624,"Two Heads Are Better Than One",1523102400,666,0
625,"Gcd Sum",1524322800,658,0
626,"Counting Binary Matrices",1525543200,235,0
627,"Counting Products",1526763600,253,0
628,"Open Chess Positions",1527984000,835,0
629,"Scatterstone Nim",1529204400,255,0
630,"Crossed Lines",1530424800,1065,0
631,"Constrained Permutations",1531645200,200,0
632,"Square Prime Factors",1532779200,506,0
633,"Square Prime Factors II",1532779200,335,0
634,"Numbers of the Form $a^2b^3$",1533999600,650,0
635,"Subset Sums",1535220000,364,0
636,"Restricted Factorisations",1536440400,202,0
637,"Flexible Digit Sum",1537660800,340,0
638,"Weighted Lattice Paths",1538881200,398,0
639,"Summing a Multiplicative Function",1540101600,279,0
640,"Shut the Box",1540720800,380,0
641,"A Long Row of Dice",1541250000,522,0
642,"Sum of Largest Prime Factors",1541865600,377,0
643,"$2$-Friendly",1542481200,642,0
644,"Squares on the Line",1543096800,171,0
645,"Every Day Is a Holiday",1543712400,221,0
646,"Bounded Divisors",1544328000,297,0
647,"Linear Transformations of Polygonal Numbers",1544943600,458,0
648,"Skipping Squares",1545559200,300,0
649,"Low-Prime Chessboard Nim",1546088400,433,0
650,"Divisors of Binomial Product",1546704000,1738,0
651,"Patterned Cylinders",1547319600,183,0
652,"Distinct Values of a Proto-logarithmic Function",1547935200,181,0
653,"Frictionless Tube",1548550800,333,0
654,"Neighbourly Constraints",1549166400,365,0
655,"Divisible Palindromes",1549782000,559,0
656,"Palindromic Sequences",1550397600,257,0
657,"Incomplete Words",1550926800,578,0
658,"Incomplete Words II",1550926800,255,0
659,"Largest Prime",1551542400,997,0
660,"Pandigital Triangles",1552158000,320,0
661,"A Long Chess Match",1552773600,238,0
662,"Fibonacci Paths",1553389200,841,0
663,"Sums of Subarrays",1554001200,375,0
664,"An Infinite Game",1554616800,200,0
665,"Proportionate Nim",1555232400,263,0
666,"Polymorphic Bacteria",1555761600,302,0
667,"Moving Pentagon",1556377200,205,0
668,"Square Root Smooth Numbers",1556992800,1105,0
669,"The King's Banquet",1557608400,330,0
670,"Colouring a Strip",1558224000,355,0
671,"Colouring a Loop",1558224000,183,0
672,"One More One",1558839600,280,0
673,"Beds and Desks",1559455200,330,0
674,"Solving $\mathcal{I}$-equations",1560070800,182,0
675,"$2^{\omega(n)}$",1560600000,783,0
676,"Matching Digit Sums",1561215600,242,0
677,"Coloured Graphs",1561831200,187,0
678,"Fermat-like Equations",1567890000,251,0
679,"Freefarea",1568505600,912,0
680,"Yarra Gnisrever",1569121200,197,0
681,"Maximal Area",1569736800,241,0
682,"$5$-Smooth Pairs",1570352400,280,0
683,"The Chase II",1570881600,337,0
684,"Inverse Digit Sum",1571497200,2811,0
685,"Inverse Digit Sum II",1571497200,212,0
686,"Powers of Two",1572112800,3594,0
687,"Shuffling Cards",1572732000,323,0
688,"Piles of Plates",1573347600,790,0
689,"Binary Series",1573963200,238,0
690,"Tom and Jerry",1574578800,219,0
691,"Long Substring with Many Repetitions",1575194400,282,0
692,"Siegbert and Jo",1575723600,1376,0
693,"Finite Sequence Generator",1576339200,299,0
694,"Cube-full Divisors",1576954800,1042,0
695,"Random Rectangles",1577570400,219,0
696,"Mahjong",1578186000,183,0
697,"Randomly Decaying Sequence",1578801600,597,0
698,"123 Numbers",1579417200,457,0
699,"Triffle Numbers",1580032800,197,0
700,"Eulercoin",1580562000,3494,0
701,"Random Connected Area",1581177600,364,0
702,"Jumping Flea",1581793200,169,0
703,"Circular Logic II",1582408800,327,0
704,"Factors of Two in Binomial Coefficients",1583024400,961,0
705,"Total Inversion Count of Divided Sequences",1583640000,449,0
706,"$3$-Like Numbers",1584255600,581,0
707,"Lights Out",1584871200,241,0
708,"Twos Are All You Need",1585400400,326,0
709,"Even Stevens",1586016000,888,0
710,"One Million Members",1586631600,1283,0
711,"Binary Blackboard",1586631600,337,0
712,"Exponent Difference",1587247200,510,0
713,"Turán's Water Heating System",1587862800,725,0
714,"Duodigits",1588478400,736,0
715,"Sextuplet Norms",1589094000,203,0
716,"Grid Graphs",1589709600,237,0
717,"Summation of a Modular Formula",1590238800,508,0
718,"Unreachable Numbers",1590854400,343,0
719,"Number Splitting",1591470000,3866,0
720,"Unpredictable Permutations",1592085600,311,0
721,"High Powers of Irrational Numbers",1592701200,430,0
722,"Slowly Converging Series",1593316800,528,0
723,"Pythagorean Quadrilaterals",1593932400,189,0
724,"Drone Delivery",1599310800,403,0
725,"Digit Sum Numbers",1599926400,1095,0
726,"Falling Bottles",1600542000,204,0
727,"Triangle of Circular Arcs",1601157600,521,0
728,"Circle of Coins",1601773200,288,0
729,"Range of Periodic Sequence",1602388800,175,0
730,"Shifted Pythagorean Triples",1603004400,187,0
731,"A Stoneham Number",1603620000,568,0
732,"Standing on the Shoulders of Trolls",1604149200,217,0
733,"Ascending Subsequences",1604764800,472,0
734,"A Bit of Prime",1605380400,333,0
735,"Divisors of $2n^2$",1605996000,222,0
736,"Paths to Equality",1606611600,234,0
737,"Coin Loops",1607227200,367,0
738,"Counting Ordered Factorisations",1607842800,283,0
739,"Summation of Summations",1608458400,514,0
740,"Secret Santa",1608987600,209,0
741,"Binary Grid Colouring",1609603200,159,0
742,"Minimum Area of a Convex Grid Polygon",1610218800,165,0
743,"Window into a Matrix",1610834400,1172,0
744,"What? Where? When?",1611450000,308,0
745,"Sum of Squares II",1612065600,1178,0
746,"A Messy Dinner",1612681200,283,0
747,"Triangular Pizza",1613296800,202,0
748,"Upside Down Diophantine Equation",1613826000,309,0
749,"Near Power Sums",1614441600,708,0
750,"Optimal Card Stacking",1615057200,324,0
751,"Concatenation Coincidence",1615672800,2282,0
752,"Powers of $1+\sqrt 7$",1616288400,651,0
753,"Fermat Equation",1616904000,398,0
754,"Product of Gauss Factorials",1617519600,707,0
755,"Not Zeckendorf",1618740000,862,0
756,"Approximating a Sum",1619874000,333,0
757,"Stealthy Numbers",1621094400,1193,0
758,"Buckets of Water",1622314800,225,0
759,"A Squared Recurrence Relation",1623535200,543,0
760,"Sum over Bitwise Operators",1624755600,423,0
761,"Runner and Swimmer",1625976000,157,0
762,"Amoebas in a 2D Grid",1630760400,208,0
763,"Amoebas in a 3D Grid",1630760400,127,0
764,"Asymmetric Diophantine Equation",1631376000,362,0
765,"Trillionaire",1631991600,220,0
766,"Sliding Block Puzzle",1633212000,323,0
767,"Window into a Matrix II",1633827600,174,0
768,"Chandelier",1634443200,172,0
769,"Binary Quadratic Form II",1635055200,142,0
770,"Delphi Flip",1635674400,502,0
771,"Pseudo Geometric Sequences",1636203600,132,0
772,"Balanceable $k$-bounded Partitions",1636819200,494,0
773,"Ruff Numbers",1637434800,201,0
774,"Conjunctive Sequences",1638050400,137,0
775,"Saving Paper",1638666000,244,0
776,"Digit Sum Division",1639281600,539,0
777,"Lissajous Curves",1639897200,125,0
778,"Freshman's Product",1640512800,400,0
779,"Prime Factor and Exponent",1641042000,476,0
780,"Toriangulations",1641657600,113,0
781,"Feynman Diagrams",1642273200,124,0
782,"Distinct Rows and Columns",1642888800,153,0
783,"Urns",1643504400,200,0
784,"Reciprocal Pairs",1644120000,391,0
785,"Symmetric Diophantine Equation",1644735600,195,0
786,"Billiard",1645351200,120,0
787,"Bézout's Game",1645880400,199,0
788,"Dominating Numbers",1646496000,1123,0
789,"Minimal Pairing Modulo $p$",1647111600,191,0
790,"Clock Grid",1647727200,259,0
791,"Average and Variance",1648342800,161,0
792,"Too Many Twos",1648958400,138,0
793,"Median of Products",1649574000,642,0
794,"Seventeen Points",1650189600,314,0
795,"Alternating GCD Sum",1650718800,349,0
796,"A Grand Shuffle",1651334400,200,0
797,"Cyclogenic Polynomials",1651950000,192,0
798,"Card Stacking Game",1652565600,122,0
799,"Pentagonal Puzzle",1653181200,231,0
800,"Hybrid Integers",1653796800,1806,0
801,"$x^y \equiv y^x$",1654412400,269,0
802,"Iterated Composition",1655028000,254,0
803,"Pseudorandom Sequence",1655557200,222,0
804,"Counting Binary Quadratic Representations",1656172800,639,0
805,"Shifted Multiples",1656788400,190,0
806,"Nim on Towers of Hanoi",1657404000,124,0
807,"Loops of Ropes",1662858000,130,0
808,"Reversible Prime Squares",1663473600,2375,0
809,"Rational Recurrence Relation ",1664089200,297,0
810,"XOR-Primes",1664704800,689,0
811,"Bitwise Recursion",1665234000,223,0
812,"Dynamical Polynomials",1665849600,128,0
813,"XOR-Powers",1666465200,535,0
814,"Mezzo-forte",1667080800,211,0
815,"Group by Value",1667696400,408,0
816,"Shortest Distance Among Points",1668312000,1886,0
817,"Digits in Squares",1668927600,441,0
818,"SET",1669543200,132,0
819,"Iterative Sampling",1670072400,220,0
820,"$N$<sup>th</sup> Digit of Reciprocals",1670688000,872,0
821,"123-Separable",1671303600,145,0
822,"Square the Smallest",1671919200,729,0
823,"Factor Shuffle",1672534800,191,0
824,"Chess Sliders",1673150400,115,0
825,"Chasing Game",1673766000,150,0
826,"Birds on a Wire",1674381600,233,0
827,"Pythagorean Triple Occurrence",1674910800,182,0
828,"Numbers Challenge",1675526400,597,0
829,"Integral Fusion",1676142000,204,0
830,"Binomials and Powers",1676757600,143,0
831,"Triple Product",1677373200,184,0
832,"Mex Sequence",1677988800,300,0
833,"Square Triangle Products",1678604400,164,0
834,"Add and Divide",1679220000,373,0
835,"Supernatural Triangles",1679749200,353,0
836,"A Bold Proposition",1680364800,2940,0
837,"Amidakuji",1680364800,202,0
838,"Not Coprime",1680980400,553,0
839,"Beans in Bowls",1681596000,341,0
840,"Sum of Products",1682211600,354,0
841,"Regular Star Polygons",1682827200,183,0
842,"Irregular Star Polygons",1683442800,124,0
843,"Periodic Circles",1684058400,123,0
844,"$k$-Markov Numbers",1684587600,203,0
845,"Prime Digit Sum",1685203200,655,0
846,"Magic Bracelets",1685818800,200,0
847,"Jack's Bean",1686434400,113,0
848,"Guessing with Sets",1687050000,189,0
849,"The Tournament",1687665600,244,0
850,"Fractions of Powers",1688281200,118,0
851,"SOP and POS",1688896800,134,0
852,"Coins in a Box",1693659600,210,0
853,"Pisano Periods 1",1694275200,978,0
854,"Pisano Periods 2",1694275200,310,0
855,"Delphi Paper",1694890800,140,0
856,"Waiting for a Pair",1695506400,497,0
857,"Beautiful Graphs",1696122000,147,0
858,"LCM",1696737600,199,0
859,"Cookie Game",1697353200,197,0
860,"Gold and Silver Coin Game",1697968800,357,0
861,"Products of Bi-Unitary Divisors",1698498000,184,0
862,"Larger Digit Permutation",1699113600,541,0
863,"Different Dice",1699729200,197,0
864,"Square + 1 = Squarefree",1700344800,142,0
865,"Triplicate Numbers",1700960400,247,0
866,"Tidying Up B",1701576000,333,0
867,"Tiling Dodecagon",1702191600,157,0
868,"Belfry Maths",1702807200,347,0
869,"Prime Guessing",1703336400,537,0
870,"Stone Game IV",1703952000,129,0
871,"Drifting Subsets",1704567600,282,0
872,"Recursive Tree",1705183200,487,0
873,"Words with Gaps",1705798800,240,0
874,"Maximal Prime Score",1706414400,359,0
875,"Quadruple Congruence",1707030000,169,0
876,"Triplet Tricks",1707645600,75,0
877,"XOR-Equation A",1708174800,274,0
878,"XOR-Equation B",1708174800,191,0
879,"Touch-screen Password",1708790400,298,0
880,"Nested Radicals",1709406000,92,0
881,"Divisor Graph Width",1710021600,317,0
882,"Removing Bits",1710637200,90,0
883,"Remarkable Triangles",1711252800,66,0
884,"Removing Cubes",1711868400,334,0
885,"Sorted Digits",1712484000,314,0
886,"Coprime Permutations",1713013200,126,0