Check out my chess queens application: http://chess-queens.sourceforge.net/

There are 14,200 ways to place 12 queens on a 12×12 chess board, and Google Chrome is the fastest browser to calculate it. If you check the number of ways to place 16 queens or rooks on a 16×16 chess board, with a minimum distance of 4 – there are only 2 ways to do this. Each of them is symmetric.

There are 92 ways to place 8 queens on a 8×8 chess board, without any queen attacking each other. The complete list of solutions is found on Wikipedia.