PlaySudoku.us
Expert · Puzzle #236
5
9
3
7
8
6
2
7
7
8
2
7
1
4
9
6
5
8
4
5
7
3
9
3
4
2
Finnish mathematician Arto Inkala created what is widely considered the world's hardest Sudoku in 2012.
Finnish mathematician Arto Inkala created what is widely considered the world's hardest Sudoku in 2012.
The hardest published Sudoku puzzle — graded by the number of search nodes a computer needs — was named 'Al Escargot' by its creator.
The hardest published Sudoku puzzle — graded by the number of search nodes a computer needs — was named 'Al Escargot' by its creator.