cp's OEIS Frontend

Define the bias of a polyomino to be the difference between the number of black squares and the number of white squares when chessboard coloring is applied to the polyomino. Maximally biased polyominoes of size n are those sharing the maximum value of bias among all polyominoes of n squares. For n = 4m + 1, for integer m, all maximally biased polyominoes may be built starting with a monomino and then successively adding "airplane" tetrominoes.

Define the bias of a polyiamond to be the difference between the number of black triangles and the number of white triangles when chessboard coloring is applied to the polyiamond. Unbiased polyiamonds are those having an equal number of black and white triangles. The sequence is defined for 2n rather than n as odd-sized polyiamonds are obviously biased.