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Search: id:A070921
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| A070921 |
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Card{ (x,y,z,u,v) | LCM(x,y,z,u,v)=n } where LCM(x,y,z,u,v) denote the least common multiple common of (x,y,z,u,v). |
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+0
2
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| 1, 31, 31, 211, 31, 961, 31, 781, 211, 961, 31, 6541, 31, 961, 961, 2101, 31, 6541, 31, 6541, 961, 961, 31, 24211, 211, 961, 781, 6541, 31, 29791, 31, 4651, 961, 961, 961, 44521, 31, 961, 961, 24211, 31, 29791, 31, 6541, 6541, 961, 31, 65131, 211, 6541
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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A048691(n) gives Card{ (x,y) | LCM(x,y)=n }
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FORMULA
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a(n)=Sum(d|n, A000005(d)^5*A008683(n/d)); Sum(k>0, a(k)/k^s)=1/zeta(s)*Sum(k>0, tau(k)^5/k^s)
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PROGRAM
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(PARI) for(n=1, 100, print1(sumdiv(n, d, numdiv(d)^5*moebius(n/d)), ", "))
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CROSSREFS
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Cf. A048691.
Sequence in context: A085320 A040931 A022365 this_sequence A133782 A022401 A042936
Adjacent sequences: A070918 A070919 A070920 this_sequence A070922 A070923 A070924
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KEYWORD
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mult,easy,nonn
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AUTHOR
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Benoit Cloitre (benoit7848c(AT)orange.fr), May 20 2002
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