A017698 Denominator of sum of -17th powers of divisors of n.

1, 131072, 129140163, 17179869184, 762939453125, 1410554953728, 232630513987207, 2251799813685248, 16677181699666569, 50000000000000000, 505447028499293771, 554652776685109248, 8650415919381337933

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

G. C. Greubel, Table of n, a(n) for n = 1..10000

Mathematica

Table[Denominator[DivisorSigma[17, n]/n^17], {n, 1, 20}] (* G. C. Greubel, Nov 05 2018 *)

Prog

(PARI) vector(20, n, denominator(sigma(n, 17)/n^17)) \\ G. C. Greubel, Nov 05 2018
(Magma) [Denominator(DivisorSigma(17, n)/n^17): n in [1..20]]; // G. C. Greubel, Nov 05 2018

Crossrefs

Cf. A017697.

Sequence in context: A222529 A069278 A190780 * A010805 A138032 A236225

Adjacent sequences: A017695 A017696 A017697 * A017699 A017700 A017701

Keyword

nonn,frac

Author

N. J. A. Sloane

Status

approved