The New Sudoku Players' Forum

[eterpg]

I tried to find out, where is the proof of Bertram Felgenhauer or someone else for this big number of possible Sudokus. Can anyone help me?

[kjellfp]

If you're asking for a proof by hand, it doesn't exist, and will probably never do. The number must some way or another be counted by a computer. But there are so many independent confirmations from various people using various algorithms, that the number is certainly believed to be true.

Some links:

http://en.wikipedia.org/wiki/Mathematics_of_Sudoku
http://www.afjarvis.staff.shef.ac.uk/sudoku/