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A130616 Number of triangular polyominoes (or polyiamonds) with perimeter at most n. 0
0, 0, 1, 2, 3, 7, 12, 28, 65, 185 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

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.

LINKS

Table of n, a(n) for n=0..9.

CROSSREFS

Cf. A131481: a(n) is the number of n-cell polyiamonds (triangular polyominoes) with perimeter n+2.

Sequence in context: A182692 A203837 A032173 * A089324 A297438 A111759

Adjacent sequences:  A130613 A130614 A130615 * A130617 A130618 A130619

KEYWORD

hard,more,nonn

AUTHOR

Tanya Khovanova, Aug 10 2007

STATUS

approved

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Last modified December 16 00:55 EST 2018. Contains 318157 sequences. (Running on oeis4.)