A056881 Number of n-celled diagonally symmetric polyominoes without holes.

0, 0, 1, 0, 2, 2, 6, 5, 21, 18, 70, 61, 239, 206, 828, 711, 2903, 2485, 10314, 8791, 37031, 31451, 134147, 113566, 489672, 413419, 1799084, 1515282, 6647009, 5586834, 24677902, 20703840, 92009606, 77067674, 344336294, 288001040, 1292929699, 1079999410, 4869184237, 4062534430

Offset

1,5

Links

Table of n, a(n) for n=1..40.

Tomás Oliveira e Silva, Enumeration of polyominoes

Crossrefs

Cf. A000104, A006748 (with holes allowed).

Sequence in context: A360087 A306768 A174399 * A260322 A286540 A229980

Adjacent sequences: A056878 A056879 A056880 * A056882 A056883 A056884

Keyword

nonn

Author

N. J. A. Sloane, Sep 03 2000

Extensions

a(29)-a(40) from John Mason, Oct 11 2022

Status

approved