A130622 Number of polyominoes with perimeter at most 2n.

0, 1, 2, 5, 11, 36, 122, 538, 2526, 13166, 71153, 400109, 2300430, 13504780, 80547558, 487327904

Offset

1,3

Comments

The perimeter of a polyomino is always even.

a(n) is partial sums of A057730.

a(n+1) >= A130866(n).

Is there another prime term beyond {2, 5, 11}?

Links

Table of n, a(n) for n=1..16.

Crossrefs

Cf. A131482 (number of n-celled polyominoes with perimeter 2n+2).

Cf. A057730 (number of polyominoes (A000105) with perimeter 2n).

Cf. A130866 (number of polyominoes with at most n cells).

Sequence in context: A353210 A295495 A343463 * A112600 A156014 A268397

Adjacent sequences: A130619 A130620 A130621 * A130623 A130624 A130625

Keyword

hard,more,nonn

Author

Tanya Khovanova, Aug 10 2007

Extensions

Offset corrected by John Mason, Jan 16 2023

a(9)-a(16) from John Mason, Jan 16 2023

Status

approved