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A003776
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Number of 2-factors in P_5 X P_2n.
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1
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3, 54, 1140, 24360, 521064, 11146656, 238452456, 5101047216, 109123156248, 2334395822496, 49938107061384, 1068291209653392, 22853211220567416, 488882861126970624
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OFFSET
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1,1
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REFERENCES
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F. Faase, On the number of specific spanning subgraphs of the graphs G X P_n, Ars Combin. 49 (1998), 129-154.
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LINKS
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FORMULA
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a(n) = 24a(n-1) - 57a(n-2) + 26a(n-3), n>3.
G.f.: 3x(1-5x)(1-x)/((1-2x)(1-22x+13x^2)). [From R. J. Mathar, Dec 16 2008]
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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