A017686 Denominator of sum of -11th powers of divisors of n.

1, 2048, 177147, 4194304, 48828125, 30233088, 1977326743, 8589934592, 31381059609, 50000000000, 285311670611, 185752092672, 1792160394037, 506195646208, 2883251953125, 17592186044416, 34271896307633

Offset

1,2

Comments

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. - Ahmed Fares (ahmedfares(AT)my-deja.com), Apr 05 2001

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Mathematica

Denominator[DivisorSigma[-11, Range[20]]] (* Harvey P. Dale, Dec 18 2012 *)

Prog

(PARI) vector(20, n, denominator(sigma(n, 11)/n^11)) \\ G. C. Greubel, Nov 06 2018
(Magma) [Denominator(DivisorSigma(11, n)/n^11): n in [1..20]]; // G. C. Greubel, Nov 06 2018

Crossrefs

Cf. A017685.

Sequence in context: A247934 A195659 A321835 * A008455 A079395 A096963

Adjacent sequences: A017683 A017684 A017685 * A017687 A017688 A017689

Keyword

nonn,frac

Author

N. J. A. Sloane

Status

approved