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A271858
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Number of ways to trisect a triangle with side length n exactly into three identical parts in a triangular lattice.
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0
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0, 1, 1, 2, 5, 20, 56, 276, 2136, 13756, 148352, 2727448, 41044816, 1056334024, 46033137324
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OFFSET
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1,4
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COMMENTS
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In the case that n is not divisible by 3 the central triangle is removed, otherwise the dissection would not be possible.
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LINKS
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Table of n, a(n) for n=1..15.
G. P. Jelliss, Trisected Triangles, The Games and Puzzles Journal, Issue 22, January-April 2002.
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CROSSREFS
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Cf. A268606, A271857, A113900, A257952.
Sequence in context: A168541 A124264 A274239 * A189734 A221678 A297350
Adjacent sequences: A271855 A271856 A271857 * A271859 A271860 A271861
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KEYWORD
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nonn,more
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AUTHOR
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Andrew Howroyd, Apr 15 2016
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STATUS
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approved
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