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A027848 a(n) = Sum_{ d|n } sigma(n/d)*d^4. 3
1, 19, 85, 311, 631, 1615, 2409, 4991, 6898, 11989, 14653, 26435, 28575, 45771, 53635, 79887, 83539, 131062, 130341, 196241, 204765, 278407, 279865, 424235, 394406, 542925, 558778, 749199, 707311, 1019065, 923553, 1278255, 1245505, 1587241, 1520079, 2145278, 1874199, 2476479, 2428875, 3149321, 2825803, 3890535, 3418845, 4557083, 4352638, 5317435 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..1000

FORMULA

Dirichlet g.f.: zeta(x-1)*zeta(x-4).

Multiplicative with a(p^e) = (p^(4e+7) - (p^3+p^2+p+1)*p^(e+1) + p^2+p+1)/(p^7 - (p^3+p^2+p+1)*p + p^2+p+1). - Mitch Harris, Jun 27 2005

L.g.f.: -log(Product_{k>=1} (1 - x^k)^sigma_3(k)) = Sum_{n>=1} a(n)*x^n/n. - Ilya Gutkovskiy, May 23 2018

PROG

(PARI)N=66; x='x+O('x^N); /* that many terms */

c=sum(j=1, N, j*x^j);

t=log(1/prod(j=1, N, eta(x^(j))^(j^3)));

Vec(serconvol(t, c)) /* show terms */

/* Joerg Arndt, May 03 2008 */

CROSSREFS

Cf. A001001, A027847, A288391.

Sequence in context: A288749 A039609 A063496 * A183623 A039454 A142089

Adjacent sequences:  A027845 A027846 A027847 * A027849 A027850 A027851

KEYWORD

nonn,mult

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified October 16 05:44 EDT 2018. Contains 316259 sequences. (Running on oeis4.)