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Search: id:A020868
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| A020868 |
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Number of single component edge-subgraphs in Moebius ladder M_n. |
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+0
1
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| 60, 397, 2464, 14809, 87000, 502261, 2859968, 16105801, 89879304, 497792981, 2739398160, 14992582713, 81664018712, 442972209365, 2394012778496, 12896089147849, 69266060508360, 371057114908533, 1983022462947472
(list; graph; listen)
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OFFSET
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2,1
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REFERENCES
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J. P. McSorley, Counting structures in the Moebius ladder, Discrete Math., 184 (1998), 137-164.
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FORMULA
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G.f.: see G in the Maple program. - Emeric Deutsch (deutsch(AT)duke.poly.edu), Dec 21 2004
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MAPLE
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G := (28*x^8-220*x^7+841*x^6-1943*x^5+2882*x^4-2746*x^3+1609*x^2-503*x+60)*x^2/(x^2-2*x+1)/(-1+6*x-5*x^2+2*x^3)^2/(1-x): Gser:=series(G, x=0, 25): seq(coeff(Gser, x^n), n=2..23); (Deutsch)
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CROSSREFS
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Sequence in context: A060489 A088942 A135037 this_sequence A088943 A097387 A057096
Adjacent sequences: A020865 A020866 A020867 this_sequence A020869 A020870 A020871
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KEYWORD
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nonn,easy
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AUTHOR
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njas
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EXTENSIONS
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More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Dec 21 2004
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