OFFSET
0,5
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..10000 (terms 0..1000 from Seiichi Manyama)
MAPLE
with(numtheory):
seq(coeff(series(mul(1+x^sigma(k), k=1..n), x, 80), x, n), n=0..70); # Muniru A Asiru, May 31 2018
MATHEMATICA
nmax = 100; CoefficientList[Series[Product[1 + x^DivisorSigma[1, k], {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Jun 03 2018 *)
PROG
(PARI) N=99; x='x+O('x^N); Vec(prod(k=1, N, 1+x^sigma(k)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, May 30 2018
STATUS
approved