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A141004
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E.g.f. exp[sum_{d|M} (exp(d*x)-1)/d], M=6.
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7
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1, 4, 28, 258, 2892, 37778, 560124, 9256010, 168182044, 3325057826, 70934634236, 1621828212826, 39517131361884, 1021237022557682, 27877344103738940, 800976143703407210, 24148078430008534428
(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, 6], {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: A191801 A064340 A002895 * A152410 A177403 A196523
Adjacent sequences: A141001 A141002 A141003 * A141005 A141006 A141007
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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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