OFFSET
0,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..10000
FORMULA
a(0) = 1, a(n) = -(2/n)*Sum_{k=1..n} A007331(k)*a(n-k) for n > 0.
G.f.: exp(Sum_{k>=1} (sigma_3(k) - sigma_3(2*k))*x^k/(4*k)). - Ilya Gutkovskiy, Apr 14 2019
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Apr 30 2017
STATUS
approved