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Search: id:A131486
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| A131486 |
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a(n) is the number of triangular polyominoes (polyiamonds) with n edges. |
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+0
1
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| 0, 0, 1, 0, 1, 0, 1, 0, 3, 0, 4, 1, 11, 1, 23, 4, 62, 11, 150, 38, 411, 118, 1081, 389
(list; graph; listen)
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OFFSET
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1,9
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COMMENT
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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.
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LINKS
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Isoperimetrical Polyiamonds at Poly Pages
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CROSSREFS
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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 this_sequence A127445 A081170 A077150
Adjacent sequences: A131483 A131484 A131485 this_sequence A131487 A131488 A131489
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KEYWORD
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hard,more,nonn
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AUTHOR
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Tanya Khovanova (tanyakh(AT)yahoo.com), Jul 28 2007
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