How many different sudoku puzzles are there? The answer: 6, 670, 903, 752, 021, 072, 936, 960, according to this site:
https://www.technologyreview.com/2012/01/06/188520/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.
http://www.afjarvis.staff.shef.ac.uk/sudoku/sudoku.pdf ${}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}$
Based on the equation (9!^2(9)), the number of possible sudoku puzzles is exactly 1,185,137,049,600.