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Search: id:A108682
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| A108682 |
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(n+1)(n+2)^2*(n+3)(n+4)(4n^2+15n+15)/720. |
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+0
1
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| 1, 17, 122, 560, 1946, 5586, 13944, 31284, 64515, 124267, 226226, 392756, 654836, 1054340, 1646688, 2503896, 3718053, 5405253, 7710010, 10810184, 14922446, 20308310, 27280760, 36211500, 47538855, 61776351, 79522002, 101468332
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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Kekule numbers for certain benzenoids.
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REFERENCES
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S. J. Cyvin and I. Gutman, Kekule structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (p.233, # 7).
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FORMULA
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G.f.=(1+9z+14z^2+4z^3)/(1-z)^8
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MAPLE
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G:=factor(sum(a(n)*z^n, n=0..infinity)); series(G, z=0, 37);
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CROSSREFS
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Sequence in context: A010823 A022709 A094944 this_sequence A031213 A021003 A023081
Adjacent sequences: A108679 A108680 A108681 this_sequence A108683 A108684 A108685
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KEYWORD
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nonn
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AUTHOR
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Emeric Deutsch (deutsch(AT)duke.poly.edu), Jun 18 2005
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