A057425 Number of rotationally symmetric 2n-celled polyominoes with 1 hole.

1, 7, 42, 193, 853, 3553, 14564, 58636, 234523

Offset

5,2

Links

Table of n, a(n) for n=5..13.

Tomás Oliveira e Silva, Enumeration of polyominoes

Crossrefs

Cf. A056883.

Sequence in context: A212144 A266387 A008526 * A248329 A073376 A094429

Adjacent sequences: A057422 A057423 A057424 * A057426 A057427 A057428

Keyword

nonn,more

Author

N. J. A. Sloane, Sep 05 2000

Status

approved