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A003693
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Number of 2-factors in P_4 X P_n.
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0
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0, 2, 3, 18, 54, 222, 779, 2953, 10771, 40043, 147462, 545603, 2013994, 7442927, 27490263, 101563680, 375176968, 1386004383, 5120092320, 18914660608, 69873991466, 258127586367, 953569519203, 3522660270539
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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REFERENCES
| 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
| F. Faase, On the number of specific spanning subgraphs of the graphs G X P_n, Preliminary version of paper that appeared in Ars Combin. 49 (1998), 129-154.
F. Faase, Counting Hamilton cycles in product graphs
F. Faase, Results from the counting program
F. Faase, Counting Hamilton cycles in product graphs
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FORMULA
| a(n) = 2a(n-1) + 7a(n-2) - 2a(n-3) - 3a(n-4) + a(n-5), n>5.
G.f.:(-x*(x-1)*(x-2)*(x+1))/(-1+x^5-3*x^4-2*x^3+7*x^2+2*x) [From Maksym Voznyy (voznyy(AT)mail.ru), Aug 10 2009]
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CROSSREFS
| Sequence in context: A064777 A137784 A053195 * A048047 A114165 A166510
Adjacent sequences: A003690 A003691 A003692 * A003694 A003695 A003696
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KEYWORD
| nonn
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AUTHOR
| Frans Faase (Frans_LiXia(AT)wxs.nl)
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