A130616 Number of triangular polyominoes (or polyiamonds) with perimeter at most n.

0, 0, 1, 2, 3, 7, 12, 28, 65, 185

Offset: 1

Author

Tanya Khovanova, Aug 10 2007

Keywords

• hard
• more
• nonn

Comments

Partial sums of A057729 - Number of triangular polyominoes (or polyiamonds) with perimeter n. a(n+2) >= A130867(n) - Triangular polyominoes (or polyiamonds) with n cells at most.

Crossrefs

Cf. A131481 (number of n-cell polyiamonds with perimeter n+2).

Extensions

Offset corrected by John Mason, Jan 16 2023