|
|
A017693
|
|
Numerator of sum of -15th powers of divisors of n.
|
|
3
|
|
|
1, 32769, 14348908, 1073774593, 30517578126, 13061093507, 4747561509944, 35185445863425, 205891146443557, 500015258805447, 4177248169415652, 3851873211923611, 51185893014090758, 19446605389919367, 48654880101420712, 1152956690052710401, 2862423051509815794
(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
|
|
|
FORMULA
|
Dirichlet g.f. of a(n)/A017694(n): zeta(s)*zeta(s+15).
Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k)/A017694(k) = zeta(16) (A013674). (End)
|
|
MATHEMATICA
|
Table[Numerator[DivisorSigma[15, n]/n^15], {n, 1, 20}] (* G. C. Greubel, Nov 06 2018 *)
|
|
PROG
|
(PARI) vector(20, n, numerator(sigma(n, 15)/n^15)) \\ G. C. Greubel, Nov 06 2018
(Magma) [Numerator(DivisorSigma(15, n)/n^15): n in [1..20]]; // G. C. Greubel, Nov 06 2018
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,frac
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|