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Problems Archives

The problems archives table shows problems 1 to 713. If you would like to tackle the 10 most recently published problems then go to Recent problems.
Click the description/title of the problem to view details and submit your answer.


IDDescription / TitleSolved By
301Nim
5917
302Strong Achilles Numbers
672
303Multiples with small digits
3302
304Primonacci
1935
305Reflexive Position
544
306Paper-strip Game
1028
307Chip Defects
1493
308An amazing Prime-generating Automaton
679
309Integer Ladders
709
310Nim Square
1003
311Biclinic Integral Quadrilaterals
389
312Cyclic paths on SierpiƄski graphs
754
313Sliding game
1448
314The Mouse on the Moon
460
315Digital root clocks
3074
316Numbers in decimal expansions
585
317Firecracker
2368
3182011 nines
811
319Bounded Sequences
354
320Factorials divisible by a huge integer
760
321Swapping Counters
1567
322Binomial coefficients divisible by 10
408
323Bitwise-OR operations on random integers
3542
324Building a tower
623
325Stone Game II
529
326Modulo Summations
464
327Rooms of Doom
1037
328Lowest-cost Search
360
329Prime Frog
2252
330Euler's Number
458
331Cross flips
348
332Spherical triangles
528
333Special partitions
1095
334Spilling the beans
415
335Gathering the beans
444
336Maximix Arrangements
1851
337Totient Stairstep Sequences
451
338Cutting Rectangular Grid Paper
290
339Peredur fab Efrawg
487
340Crazy Function
987
341Golomb's self-describing sequence
850
342The totient of a square is a cube
720
343Fractional Sequences
1267
344Silver dollar game
274
345Matrix Sum
5145
346Strong Repunits
3899
347Largest integer divisible by two primes
4137
348Sum of a square and a cube
2707
349Langton's ant
1724
350Constraining the least greatest and the greatest least
427