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Problems Archives

The problems archives table shows problems 1 to 745. 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.


ID

Description / TitleSolved By
401Sum of squares of divisors
2377
402Integer-valued polynomials
360
403Lattice points enclosed by parabola and line
329
404Crisscross Ellipses
295
405A rectangular tiling
553
406Guessing Game
343
407Idempotents
2283
408Admissible paths through a grid
524
409Nim Extreme
423
410Circle and tangent line
258
411Uphill paths
589
412Gnomon numbering
459
413One-child Numbers
352
414Kaprekar constant
251
415Titanic sets
275
416A frog's trip
272
417Reciprocal cycles II
785
418Factorisation triples
634
419Look and say sequence
448
4202x2 positive integer matrix
405
421Prime factors of n15+1
593
422Sequence of points on a hyperbola
248
423Consecutive die throws
445
424Kakuro
363
425Prime connection
1347
426Box-ball system
237
427n-sequences
276
428Necklace of circles
221
429Sum of squares of unitary divisors
2379
430Range flips
794
431Square Space Silo
562
432Totient sum
442
433Steps in Euclid's algorithm
442
434Rigid graphs
317
435Polynomials of Fibonacci numbers
1009
436Unfair wager
419
437Fibonacci primitive roots
713
438Integer part of polynomial equation's solutions
251
439Sum of sum of divisors
351
440GCD and Tiling
343
441The inverse summation of coprime couples
329
442Eleven-free integers
360
443GCD sequence
1048
444The Roundtable Lottery
280
445Retractions A
341
446Retractions B
322
447Retractions C
258
448Average least common multiple
305
449Chocolate covered candy
833
450Hypocycloid and Lattice points
177