OFFSET
0,2
PROG
(PARI) {a(n)=local(A); if(n<0, 0, A=x*O(x^n); polcoeff( eta(x+A)^2*sum(k=1, n, 240*sigma(k, 3)*x^k, 1+A)^2, n))}
CROSSREFS
KEYWORD
sign
AUTHOR
Michael Somos, Aug 28 2006
STATUS
approved