1,9

An n-celled polyiamond with perimeter p has (3n+p)/2 edges. The maximum number of edges in an n-celled polyiamond is 2n+1.

Table of n, a(n) for n=1..24.

Isoperimetrical Polyiamonds at Poly Pages

Cf. A000577: Triangular polyominoes (or polyiamonds) with n cells. A057729: Number of triangular polyominoes (or polyiamonds) [A000577] with perimeter n. A131481: a(n) is the number of n-cell polyiamonds (triangular polyominoes) with perimeter n+2.

Sequence in context: A138376 A077140 A003815 * A127445 A081170 A201291

Adjacent sequences: A131483 A131484 A131485 * A131487 A131488 A131489

hard,more,nonn

Tanya Khovanova, Jul 28 2007

approved