A056882 Number of n-celled polyominoes without holes, symmetric about diagonal 2.

0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 2, 1, 2, 3, 4, 4, 6, 7, 12, 12, 17, 18, 33, 34, 51, 52, 93, 100, 154, 152, 276, 300, 474, 460, 846, 929, 1491, 1431, 2667, 2956

Offset: 1

Author

N. J. A. Sloane, Sep 03 2000

Keywords

• nonn
• more

Links

• Tomás Oliveira e Silva, Enumeration of polyominoes

Crossrefs

Cf. A000104, A056878 (with holes allowed).

Extensions

a(29)-a(40) from John Mason, Oct 10 2022