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A017694 Denominator of sum of -15th powers of divisors of n. 3


%S 1,32768,14348907,1073741824,30517578125,13060694016,4747561509943,

%T 35184372088832,205891132094649,500000000000000,4177248169415651,

%U 3851755393646592,51185893014090757,19446011944726528,48654876708984375

%N Denominator of sum of -15th 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="/A017694/b017694.txt">Table of n, a(n) for n = 1..10000</a>

%t Table[Denominator[DivisorSigma[15, n]/n^15], {n, 1, 20}] (* _G. C. Greubel_, Nov 05 2018 *)

%o (PARI) vector(20, n, denominator(sigma(n, 15)/n^15)) \\ _G. C. Greubel_, Nov 05 2018

%o (MAGMA) [Denominator(DivisorSigma(15,n)/n^15): n in [1..20]]; // _G. C. Greubel_, Nov 05 2018

%Y Cf. A017693.

%K nonn,frac

%O 1,2

%A _N. J. A. Sloane_

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Last modified May 25 16:40 EDT 2020. Contains 334595 sequences. (Running on oeis4.)