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A052143
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E.g.f.: exp(x)/sqrt(1-4*x).
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0
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1, 3, 17, 163, 2241, 39971, 874513, 22652547, 677742593, 22996109251, 872449527441, 36595485309923, 1681600030358977, 84005018253431523, 4532832802360066961, 262732854317051785411, 16280199853832658463233, 1073958487530496802770307
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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REFERENCES
| R. P. Stanley, Enumerative Combinatorics, Cambridge, Vol. 2, 1999; see page 191.
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LINKS
| Vladimir Kruchinin, Compositae and their properties , arXiv:1103.2582
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FORMULA
| a(n)=n!*sum(a000984(k)/(n-k)!,k,0,n)=sum(binomial(n,k)*(2*k)!/(k!),k,0,n) [From Kruchinin Vladimir (kru(AT)ie.tusur.ru), Sep 10 2010]
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CROSSREFS
| Sequence in context: A066211 A163884 A175607 * A069856 A015083 A053934
Adjacent sequences: A052140 A052141 A052142 * A052144 A052145 A052146
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Jan 23 2000
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