The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A017712 Denominator of sum of -24th powers of divisors of n. 73

%I #16 Sep 08 2022 08:44:43

%S 1,16777216,282429536481,281474976710656,59604644775390625,

%T 2369190669160808448,191581231380566414401,4722366482869645213696,

%U 79766443076872509863361,500000000000000000000000,9849732675807611094711841

%N Denominator of sum of -24th powers of divisors of n.

%C 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 G. C. Greubel, <a href="/A017712/b017712.txt">Table of n, a(n) for n = 1..1000</a>

%t Table[Denominator[DivisorSigma[24, n]/n^24], {n, 1, 20}] (* _G. C. Greubel_, Nov 03 2018 *)

%o (PARI) a(n) = denominator(sigma(n, 24)/n^24); \\ _Michel Marcus_, Nov 01 2013

%o (Magma) [Denominator(DivisorSigma(24,n)/n^24): n in [1..20]]; // _G. C. Greubel_, Nov 03 2018

%Y Cf. A017711.

%K nonn,frac

%O 1,2

%A _N. J. A. Sloane_

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 13 00:21 EDT 2024. Contains 373362 sequences. (Running on oeis4.)