A056879 Number of n-celled axially symmetric polyominoes without holes.

0, 0, 0, 1, 2, 6, 9, 23, 37, 87, 138, 313, 510, 1130, 1859, 4070, 6786, 14750, 24811, 53715, 91096, 196769, 335815, 724470, 1243175, 2680212, 4619999, 9957652, 17231447, 37137177, 64480255, 138978282, 242011375, 521706359, 910817416, 1963885190, 3436463468, 7411495499, 12995261895, 28034824487

Offset: 1

Author

N. J. A. Sloane, Sep 03 2000

Keywords

• nonn

Links

• Tomás Oliveira e Silva, Enumeration of polyominoes

Crossrefs

Cf. A000105, A000104, A006746.

Extensions

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