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A145400
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Number of 2-factors in P_6 X P_n.
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0
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0, 5, 9, 222, 1140, 13903, 99051, 972080, 7826275, 71053230, 599141127, 5285091303, 45349095730
(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
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FORMULA
| Recurrence: a(1) = 0,
a(2) = 5,
a(3) = 9,
a(4) = 222,
a(5) = 1140,
a(6) = 13903,
a(7) = 99051,
a(8) = 972080,
a(9) = 7826275,
a(10) = 71053230,
a(11) = 599141127,
a(12) = 5285091303,
a(13) = 45349095730, and
for n >= 14, a(n) = 5a(n-1) + 49a(n-2) - 116a(n-3) - 363a(n-4) + 627a(n-5)
+ 544a(n-6) - 1061a(n-7) + 133a(n-8) + 264a(n-9) - 47a(n-10)
- 26a(n-11) + 3a(n-12) + a(n-13).
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CROSSREFS
| Sequence in context: A098097 A097397 A092584 * A002657 A046093 A097086
Adjacent sequences: A145397 A145398 A145399 * A145401 A145402 A145403
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KEYWORD
| nonn,more
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Feb 03 2009
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