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0,4
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.
Table of n, a(n) for n=0..9.
Cf. A131481: a(n) is the number of n-cell polyiamonds (triangular polyominoes) with perimeter n+2.
Sequence in context: A182692 A203837 A032173 * A089324 A111759 A047749
Adjacent sequences: A130613 A130614 A130615 * A130617 A130618 A130619
hard,more,nonn
Tanya Khovanova, Aug 10 2007
approved