Ferrers graph polyomino
A Ferrers graph is a polyomino represented by a Ferrers diagram, a way to represent a partition of a number. It consists of a stack of rows that are left-aligned and decreasing in size. It is equivalent to a convex polyomino that contains three of the four corners of its bounding box, which makes it both a stack polyomino and a staircase polyomino, since it contains both opposite and adjacent corners.