# How many different sudoku puzzles are there?

The answer: 6, 670, 903, 752, 021, 072, 936, 960, according to this site:

http://www.technologyreview.com/view/426554/mathematicians-solve-minimum-sudoku-problem/

I have tried to get this number using direct methods but basically I have found the question too hard. There are too many possibilities, but I am likely missing some strategic ways to solve the problem. Any help would be greatly appreciated, thanks.

-
You should be more precise about when two give sudokus are different. For example given some sudokus you can use a rotation to get a new one. Or another way is just renaming the 1 into 2 and vice versa –  Dominic Michaelis Nov 20 '13 at 6:04
So as in Wikipedia stand there are actually 5,472,730,538 different sudokus (taken symmetries in account) –  Dominic Michaelis Nov 20 '13 at 6:06

http://www.afjarvis.staff.shef.ac.uk/sudoku/sudoku.pdf ${}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}$