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Search: id:A097125
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| A097125 |
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Number of noncongruent integer-sided tetrahedra with largest side n. |
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+0
3
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| 1, 4, 16, 45, 116, 254, 516, 956, 1669, 2760, 4379, 6676, 9888, 14219, 19956, 27421, 37062, 49143, 64272, 82888, 105629, 133132, 166090, 205223, 251624, 305861, 369247, 442695, 527417, 624483, 735777, 861885, 1005214, 1166797, 1348609
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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From Kurtz's abstract: We determine the numbers of integral tetrahedra with diameter d up to isomorphism for all d <= 1000 via computer enumeration. Therefore we give an algorithm that enumerates the integral tetrahedra with diameter at most d in O(d^5) time and an algorithm that can check the canonicity of a given integral tetrahedron with at most 6 integer comparisons. For the number of isomorphism classes of integral 4x4 matrices with diameter d fulfilling the triangle inequalities we derive an exact formula. - Jonathan Vos Post (jvospost3(AT)gmail.com), Apr 10 2008
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LINKS
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N. J. A. Sloane, Table of n, a(n) for n = 1..100 [Extracted from the Kurtz link]
Sascha Kurz, Enumeration of integral tetrahedra
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CROSSREFS
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Cf. A000065, A002620, A097126, A097127.
Adjacent sequences: A097122 A097123 A097124 this_sequence A097126 A097127 A097128
Sequence in context: A018210 A054498 A134139 this_sequence A000704 A007315 A055342
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KEYWORD
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nonn
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AUTHOR
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Sascha Kurz (sascha.kurz(AT)uni-bayreuth.de), Jul 26 2004
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