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A017702 Denominator of sum of -19th powers of divisors of n. 3
1, 524288, 1162261467, 274877906944, 19073486328125, 50779978334208, 11398895185373143, 144115188075855872, 1350851717672992089, 5000000000000000000, 61159090448414546291, 79869999842655731712 (list; graph; refs; listen; history; text; internal format)
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[19, n]/n^19], {n, 1, 20}] (* G. C. Greubel, Nov 05 2018 *)

PROG

(PARI) vector(20, n, denominator(sigma(n, 19)/n^19)) \\ G. C. Greubel, Nov 05 2018

(MAGMA) [Denominator(DivisorSigma(19, n)/n^19): n in [1..20]]; // G. C. Greubel, Nov 05 2018

CROSSREFS

Cf. A017701.

Sequence in context: A289480 A222530 A069280 * A010807 A236227 A320345

Adjacent sequences:  A017699 A017700 A017701 * A017703 A017704 A017705

KEYWORD

nonn,frac

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified March 30 19:28 EDT 2020. Contains 333127 sequences. (Running on oeis4.)