GAME-001
Open
Sudoku: Unique Solution Puzzles
How many Sudoku puzzles have exactly one solution?...
L2
892
67
GAME-002
Open
Sudoku: Minimal Puzzles Count
How many Sudoku puzzles with exactly one solution are minimal (removing any clue creates multiple solutions)?...
L2
678
51
GAME-003
Open
Maximum Givens in Minimal Sudoku
What is the maximum number of givens for a minimal Sudoku puzzle?...
L2
567
43
GUY-A15
Open
Congruent Products of Consecutive Numbers
What is the least prime $p$ such that there are integers $a, k_1, k_2, k_3$ with $\prod_{i=1}^{k_1} (a+i) \equiv \prod_{i=1}^{k_2} (a+k_1+i) \equiv \p...
L2
0
0
GUY-A19b
Open
Cohen-Selfridge Problem on $\pm p^a \pm 2^b$
What is the least positive odd number not of the form $\pm p^a \pm 2^b$, where $p$ is an odd prime?...
L2
0
0
EP-952
Open
Erdős Problem #952
Is there an infinite sequence of distinct Gaussian primes $x_1,x_2,\ldots$ such that $ \lvert x_{n+1}-x_n\rvert \ll 1? $ ...
L2
0
0