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Search: id:A069097
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| A069097 |
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Moebius transform of f[x]=x*sigma[x]. |
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+0
5
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| 1, 5, 11, 22, 29, 55, 55, 92, 105, 145, 131, 242, 181, 275, 319, 376, 305, 525, 379, 638, 605, 655, 551, 1012, 745, 905, 963, 1210, 869, 1595, 991, 1520, 1441, 1525, 1595, 2310, 1405, 1895, 1991, 2668, 1721, 3025, 1891, 2882, 3045, 2755, 2255, 4136, 2737
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Equals A127569 * [1, 2, 3,...] - Gary W. Adamson (qntmpkt(AT)yahoo.com), Jan 19 2007
Equals row sums of triangle A143309 [From Gary W. Adamson (qntmpkt(AT)yahoo.com), Aug 06 2008]
Equals row sums of triangle A143312 [From Gary W. Adamson (qntmpkt(AT)yahoo.com), Aug 06 2008]
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FORMULA
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a(n) = Sum_{d|n} d^2*phi(n/d). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Jul 31 2002
a(n) = Sum_{k=1..n} gcd(n, k)^2. - Vladeta Jovovic (vladeta(AT)Eunet.yu), Aug 27 2003
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PROGRAM
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(PARI) for(n=1, 100, print1((sumdiv(n, k, k*sigma(k)*moebius(n/k))), ", "))
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CROSSREFS
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Cf. A033457, A068963.
Cf. A127569.
Cf. A143309, A143312. [From Gary W. Adamson (qntmpkt(AT)yahoo.com), Aug 06 2008]
Sequence in context: A139534 A093328 A131898 this_sequence A024921 A143127 A061769
Adjacent sequences: A069094 A069095 A069096 this_sequence A069098 A069099 A069100
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KEYWORD
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easy,nonn,mult
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AUTHOR
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Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 05 2002
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