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A064312
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B(n)*P(n), where B(n) are Bell numbers (A000110) and P(n) are numbers of arrangements of a set of n elements (A000522).
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1
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1, 2, 10, 80, 975, 16952, 397271, 12014900, 453748140, 20859612270, 1143989113475, 73628313849840, 5486361777107965, 467931786713485382, 45238398292112762210, 4915902436799253089420, 596048018991814531136899
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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FORMULA
| Integral representation as n-th moment of a positive function on a positive half-axis, in Maple notation: a(n)= int(x^n*sum(exp(-x/k)*Heaviside(x-k)/(k*k!), k=1..infinity), x=0..infinity)
E.g.f.: A(x) = Sum_{n>=0} exp(n*x-1)/(n!*(1-n*x)). - Vladeta Jovovic (vladeta(AT)eunet.rs), Feb 04 2008
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MAPLE
| a:=n->sum(bell(n)*n!/j!, j=0..n):seq(a(n), n=0..16); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Mar 19 2007
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CROSSREFS
| Cf. A000110, A000522.
Sequence in context: A048286 A133480 A008544 * A063902 A088351 A174962
Adjacent sequences: A064309 A064310 A064311 * A064313 A064314 A064315
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KEYWORD
| nonn
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AUTHOR
| Karol A. Penson (penson(AT)lptl.jussieu.fr), Sep 07 2001
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