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Search: id:A000426
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| A000426 |
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Coefficients of menage hit polynomials.
(Formerly M4515 N1910)
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+0
3
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| 0, 1, 1, 1, 8, 35, 211, 1459, 11584, 103605, 1030805, 11291237, 135015896, 1749915271, 24435107047, 365696282855, 5839492221440, 99096354764009, 1780930394412009, 33789956266629001, 674939337282352360, 14157377139256183723
(list; graph; listen)
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OFFSET
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1,5
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REFERENCES
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J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 198.
H. M. Taylor, A problem on arrangements, Mess. Math., 32 (1902), 60ff.
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LINKS
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David W. Wilson, Table of n, a(n) for n = 1..100
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FORMULA
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a(n) = SUM(k = 2..n, ((-1)^k (2n-k-1)! (n-k)!)/((2n-2k)! (k-2)!))
a(n) = A000033(n)/n.
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MAPLE
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a(n) = ((2n-5)a(n-1) + (5n-11)a(n-2) + (5n-14)a(n-3) + (2n-5)a(n-4) + 2a(n-5))/2 for n >= 6.
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CROSSREFS
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Cf. A000179, A000271. A diagonal of A058057.
Sequence in context: A094616 A114569 A098999 this_sequence A089698 A133887 A057345
Adjacent sequences: A000423 A000424 A000425 this_sequence A000427 A000428 A000429
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KEYWORD
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nonn,easy
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AUTHOR
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njas and Simon Plouffe (plouffe(AT)math.uqam.ca)
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EXTENSIONS
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Edited by David W. Wilson, Dec 27 2007
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