curiosamathematica:All 369 distinct octominoes (polyominoes, or tetris pieces, with 8 cell
curiosamathematica:All 369 distinct octominoes (polyominoes, or tetris pieces, with 8 cells) can perfectly cover a rectangle together, except for the 6 pieces which contain a hole. Here these 6 quarrellers are nicely aligned in the center of the tiling. -- source link