A130867 Triangular polyominoes (or polyiamonds) with n cells at most (turning over is allowed, holes are allowed, must be connected along edges).

1, 2, 3, 6, 10, 22, 46, 112, 272, 720, 1906, 5240, 14475, 40641, 114624, 325921, 930028, 2666356, 7666949, 22115933, 63951671, 185370931, 538416222, 1566868939, 4567669566, 13336886288, 38998848186, 114194014853

Offset

1,2

Links

Table of n, a(n) for n=1..28.

Crossrefs

Partial sums of A000577.

Sequence in context: A052817 A156803 A002992 * A218210 A122381 A141034

Adjacent sequences: A130864 A130865 A130866 * A130868 A130869 A130870

Keyword

nonn

Author

Tanya Khovanova, Jul 23 2007

Status

approved