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Search: id:A081543
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| A081543 |
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G.f.: sum(k>=1,x^k/(1-x^k)^(k+1)). |
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+0
3
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| 1, 3, 4, 8, 6, 17, 8, 24, 20, 32, 12, 76, 14, 51, 72, 97, 18, 158, 20, 213, 142, 101, 24, 491, 152, 132, 248, 479, 30, 915, 32, 681, 398, 206, 828, 1859, 38, 249, 600, 2560, 42, 2692, 44, 1686, 2864, 347, 48, 6166, 1766, 3405
(list; graph; listen)
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OFFSET
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1,2
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FORMULA
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If p is prime then a(p)=p+1.
a(n) = sum_{d|n} binomial(d-1+n/d,d). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 21 2009
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PROGRAM
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(PARI) a(n)=if(n<1, 0, polcoeff(sum(k=1, n, 1/(1-x^k)^k, x*O(x^(n^2))), n))
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CROSSREFS
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Sequence in context: A129283 A079787 A081307 this_sequence A105753 A019972 A064406
Adjacent sequences: A081540 A081541 A081542 this_sequence A081544 A081545 A081546
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KEYWORD
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nonn
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AUTHOR
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Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 21 2003
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EXTENSIONS
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Description corrected by Vladeta Jovovic (vladeta(AT)eunet.rs), Aug 22 2003
Corrected offset R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 21 2009
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