OFFSET
1,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..213
FORMULA
G.f.: Sum_{k>0} k^(2*k+2)*x^k/(1-(k^2*x)^k).
PROG
(PARI) {a(n) = sigma(n, 2*n+2)}
(PARI) N=20; x='x+O('x^N); Vec(sum(k=1, N, k^(2*k+2)*x^k/(1-(k^2*x)^k)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Nov 12 2017
STATUS
approved