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} A076577(k)*a(n-k) for n > 0.
G.f.: exp(Sum_{k>=1} (sigma_2(k) - sigma_2(2*k))*x^k/(2*k)). - Ilya Gutkovskiy, Apr 14 2019
G.f.: exp( - 2*Sum_{n >= 0} x^(2*n+1)/((2*n+1)*(1 - x^(2*n+1))^2) ). Cf. A000122. - Peter Bala, Dec 23 2021
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Apr 30 2017
STATUS
approved