A130623 Number of polyhexes with perimeter at most 2n.

0, 0, 1, 1, 2, 3, 6, 8, 20, 34, 84, 182

Offset

1,5

Comments

The perimeter of a polyhex is always even.

Partial sums of A057779.

a(2n+1) >= A131467(n).

Links

Table of n, a(n) for n=1..12.

Crossrefs

Cf. A038142 (planar cata-polyhexes with n cells).

Cf. A057779 (hexagonal polyominoes with perimeter 2n).

Cf. A131467 (planar polyhexes with at most n cells).

Sequence in context: A064450 A217137 A248824 * A072847 A274371 A339589

Adjacent sequences: A130620 A130621 A130622 * A130624 A130625 A130626

Keyword

hard,more,nonn

Author

Tanya Khovanova, Aug 11 2007

Extensions

Offset corrected by John Mason, Jan 16 2023

Status

approved