A057422 Axially symmetric (about axis 2) 2n-celled polyominoes with 1 hole.

0, 2, 4, 12, 24, 57, 112, 244, 483, 998, 1979

Offset

4,2

Links

Table of n, a(n) for n=4..14.

Tomás Oliveira e Silva, Enumeration of polyominoes

Crossrefs

Cf. A056880.

Sequence in context: A004645 A045687 A233411 * A036045 A331392 A100538

Adjacent sequences: A057419 A057420 A057421 * A057423 A057424 A057425

Keyword

nonn,more

Author

N. J. A. Sloane, Sep 05 2000

Status

approved