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Search: id:A055225
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| A055225 |
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a(n) = sum{ k divides n } (n/k)^k. |
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+0
6
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| 1, 3, 4, 9, 6, 24, 8, 41, 37, 68, 12, 258, 14, 192, 384, 593, 18, 1557, 20, 2794, 2552, 2192, 24, 16730, 3151, 8388, 20440, 35394, 30, 116474, 32, 135457, 178512, 131396, 94968, 1111035, 38, 524688, 1596560, 2530986, 42, 7280934, 44, 8403778
(list; graph; listen)
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OFFSET
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1,2
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LINKS
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Nick Hobson, Table of n, a(n) for n = 1..1000
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FORMULA
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G.f.: Sum_{n=1..inf} -ln(1 - n*x^n)/n = Sum_{n=0..inf} a(n) x^n/n. - Paul D. Hanna (pauldhanna(AT)juno.com), Aug 04 2002
G.f.: Sum_{n>0} n*x^n/(1-n*x^n). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Sep 02 2002
G.f.: sum(k>=1, k*x^k/(1-k*x^k)). - Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 21 2003
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EXAMPLE
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a(10) = 10^1 +5^2 +2^5 +1^10 = 68 because positive divisors of 10 are 1, 2, 5, 10.
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PROGRAM
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(PARI) vector(44, n, sumdiv(n, d, (n/d)^d))
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CROSSREFS
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Sequence in context: A003959 A083111 A132065 this_sequence A054791 A062319 A022463
Adjacent sequences: A055222 A055223 A055224 this_sequence A055226 A055227 A055228
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KEYWORD
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nonn
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AUTHOR
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Leroy Quet (qq-quet(AT)mindspring.com), Jun 20 2000
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EXTENSIONS
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More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jul 04 2000
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