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A006902
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(2n)! Sum (-1)^k binomial(n,k) / (n+k)!.
(Formerly M4003)
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32
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1, 5, 47, 641, 11389, 248749, 6439075, 192621953, 6536413529, 248040482741, 10407123510871, 478360626529345, 23903857657114837, 1290205338991689821, 74803882225482661259
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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REFERENCES
| J. D. Horton and A. Kurn, Counting sequences with complete increasing subsequences, Congress. Numerantium, 33 (1981), 75-80.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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FORMULA
| n!*LaguerreL(n, n, 1). - Vladeta Jovovic (vladeta(AT)eunet.rs), May 11 2003
(n-2)*a(n)-(n^3+n^2-7*n+4)*a(n-1)+2*(2*n-3)*(n-1)^3*a(n-2) = 0. - Vladeta Jovovic (vladeta(AT)eunet.rs), Jul 16 2004
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MATHEMATICA
| Table[(-1)^k HypergeometricU[-k, 1 + k, 1], {k, 1, 10}] (* Vladimir Reshetnikov (v.reshetnikov(AT)gmail.com), Feb 16 2011 *)
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CROSSREFS
| Cf. A047909.
Cf. A082545.
Sequence in context: A136023 A074192 A058806 * A180254 A127696 A088691
Adjacent sequences: A006899 A006900 A006901 * A006903 A006904 A006905
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KEYWORD
| nonn,easy
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AUTHOR
| Simon Plouffe, N. J. A. Sloane (njas(AT)research.att.com).
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