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A141003
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E.g.f. exp[sum_{d|M} (exp(d*x)-1)/d], M=4.
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7
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1, 3, 16, 111, 931, 9066, 99925, 1224579, 16466524, 240481659, 3783550243, 63705870894, 1141642250521, 21673475232051, 434151377912680, 9144596750676663, 201921333704487283, 4661560653703827474
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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MATHEMATICA
| u[0, j_]:=1; u[k_, j_]:=u[k, j]=Sum[Binomial[k-1, i-1]Plus@@(u[k-i, j]#^(i-1)&/@Divisors[j]), {i, k}]; Table[u[n, 4], {n, 0, 12}] [From Wouter Meeussen (wouter.meeussen(AT)pandora.be), Dec 06 2008]
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CROSSREFS
| u[n,j] generates for j=1, A000110 Bell numbers; j=2, A002872 "Sorting numbers"; j=3, A002874 "Sorting numbers"; j=4, A141003 (Mathar); j=5, A036075 "Sorting numbers"; j=6, A141004 (Mathar); j=7, A036077 "Sorting numbers" [From Wouter Meeussen (wouter.meeussen(AT)pandora.be), Dec 06 2008]
Sequence in context: A180609 A074540 A039751 * A002404 A097142 A005419
Adjacent sequences: A141000 A141001 A141002 * A141004 A141005 A141006
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KEYWORD
| nonn
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AUTHOR
| Richard Mathar (mathar(AT)strw.leidenuniv.nl), Jul 11 2008
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