OFFSET
1,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Stieltjes Constants
Wikipedia, Stieltjes constants
FORMULA
MATHEMATICA
nmax = 50; Accumulate[Table[k^2*Sum[DivisorSigma[0, d], {d, Divisors[k]}], {k, 1, nmax}]]
PROG
(PARI) tau_3(k) = vecprod(apply(e -> (e+1)*(e+2)/2, factor(k)[, 2]));
a(n) = sum(k = 1, n, k^2 * tau_3(k)); \\ Amiram Eldar, Jan 18 2025
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Sep 10 2018
STATUS
approved