OFFSET
0,2
COMMENTS
When is a(n) zero (A258867)?
LINKS
Paul D. Hanna, Table of n, a(n) for n = 0..1024
FORMULA
EXAMPLE
G.f. = 1 - 9*x + 30*x^2 - 39*x^3 + 18*x^5 + 49*x^6 - 192*x^8 + 110*x^9 + ...
PROG
(PARI) {a(n)=polcoeff(exp(sum(m=1, n, -3*sigma(2*m)*x^m/m)+x*O(x^n)), n)}
(PARI) {a(n)=local(X=x+x*O(x^n)); polcoeff(eta(X)^9/eta(X^2)^3, n)}
CROSSREFS
KEYWORD
sign
AUTHOR
Paul D. Hanna, Feb 16 2011
STATUS
approved