264719566561domain: NAppears in sequencesThe number of tilings of an n X n rectangle using integer length rectangles with at least one side of length 1, i.e., tiles are of size (1 X i) or (i X 1) with 1<=i<=n.at n=6A254127Number of tilings of a 6 X n rectangle using polyominoes of shape I.at n=6A254458