PlaySudoku.us
Evil · Puzzle #215
4
7
1
9
3
2
3
6
1
8
2
6
1
9
7
4
2
8
3
4
2
7
3
The 4×4 mini-Sudoku is called 'Shidoku' and can be solved without any pencil marks — it's a common puzzle for children.
The 4×4 mini-Sudoku is called 'Shidoku' and can be solved without any pencil marks — it's a common puzzle for children.
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.