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A001159
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sigma_4(n): sum of 4th powers of divisors of n.
(Formerly M5041 N2177)
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31
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1, 17, 82, 273, 626, 1394, 2402, 4369, 6643, 10642, 14642, 22386, 28562, 40834, 51332, 69905, 83522, 112931, 130322, 170898, 196964, 248914, 279842, 358258, 391251, 485554, 538084, 655746, 707282, 872644, 923522, 1118481, 1200644
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| If the canonical factorization of n into prime powers is the product of p^e(p) then sigma_k(n) = Product_p ((p^((e(p)+1)*k))-1)/(p^k-1).
Sum_{d|n} 1/d^k is equal to sigma_k(n)/n^k. So sequences A017665-A017712 also give the numerators and denominators of sigma_k(n)/n^k for k = 1..24. The power sums sigma_k(n) are in sequences A000203 (k=1), A001157-A001160 (k=2,3,4,5), A013954-A013972 for k = 6,7,...,24. - comment from Ahmed Fares (ahmedfares(AT)my-deja.com), Apr 05 2001.
sigma_4(n) is the sum of the 4th powers of the divisors of n (A001159).
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REFERENCES
| M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math.Series 55, Tenth Printing, 1972, p. 827.
T. M. Apostol, Introduction to Analytic Number Theory, Springer-Verlag, 1976, page 38.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
| T. D. Noe, Table of n, a(n) for n = 1..10000
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math.Series 55, Tenth Printing, 1972, p. 827.
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FORMULA
| Multiplicative with a(p^e) = (p^(4e+4)-1)/(p^4-1). - David W. Wilson (davidwwilson(AT)comcast.net), Aug 01, 2001.
G.f. sum(k>=1, k^4*x^k/(1-x^k)). - Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 21 2003
L.g.f.: -log(prod(j>=1 ,(1-x^j)^(j^3))) = sum(n>=1, a(n)/n*x^n) - Joerg Arndt, Feb 04 2011
Dirichlet g.f.: zeta(s)*zeta(s-4). - R. J. Mathar, Feb 04 2011
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MAPLE
| with(numtheory); A001159 := proc(n) sigma[4](n) ; end proc: # R. J. Mathar, Feb 04 2011
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MATHEMATICA
| lst={}; Do[AppendTo[lst, DivisorSigma[4, n]], {n, 5!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Mar 11 2009]
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PROG
| (PARI) N=99; q='q+O('q^N);
Vec(sum(n=1, N, n^4*q^n/(1-q^n))) /* show terms, Joerg Arndt, Feb 04 2011 */
(Other) sage: [sigma(n, 4)for n in xrange(1, 34)] # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 04 2009]
(Maxima) makelist(divsum(n, 4), n, 1, 100); [Emanuele Munarini, Mar 26 2011]
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CROSSREFS
| Cf. A000005, A000203, A001157, A001158.
Sequence in context: A034678 A065960 A017671 * A053820 A142059 A193046
Adjacent sequences: A001156 A001157 A001158 * A001160 A001161 A001162
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KEYWORD
| nonn,easy,mult
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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