cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A017694 Denominator of sum of -15th powers of divisors of n.

This page as a plain text file.
%I A017694 #14 Sep 08 2022 08:44:43
%S A017694 1,32768,14348907,1073741824,30517578125,13060694016,4747561509943,
%T A017694 35184372088832,205891132094649,500000000000000,4177248169415651,
%U A017694 3851755393646592,51185893014090757,19446011944726528,48654876708984375
%N A017694 Denominator of sum of -15th powers of divisors of n.
%C A017694 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
%H A017694 G. C. Greubel, <a href="/A017694/b017694.txt">Table of n, a(n) for n = 1..10000</a>
%t A017694 Table[Denominator[DivisorSigma[15, n]/n^15], {n, 1, 20}] (* _G. C. Greubel_, Nov 05 2018 *)
%o A017694 (PARI) vector(20, n, denominator(sigma(n, 15)/n^15)) \\ _G. C. Greubel_, Nov 05 2018
%o A017694 (Magma) [Denominator(DivisorSigma(15,n)/n^15): n in [1..20]]; // _G. C. Greubel_, Nov 05 2018
%Y A017694 Cf. A017693.
%K A017694 nonn,frac
%O A017694 1,2
%A A017694 _N. J. A. Sloane_