20 ways to tile the 8x8 chessboard (excluding the middle 2x2 square) with pentominoes. There are 12 different pentominoes and each pentomino must be used exactly once. The algorithm finds 520 different solutions (if rotations and reflections are considered to be different). You can edit the code if you want to display more solutions or if you want to edit other parameters like the size of the drawings etc..