OFFSET
0,2
COMMENTS
EXAMPLE
G.f.: 1 + 2*x - 2*x^3 + 6*x^4 + 12*x^5 - 8*x^7 + 24*x^8 + 44*x^9 +...
PROG
(PARI) {a(n)=local(SQ=sum(m=0, sqrtint(n+1), x^(m^2))+x*O(x^n), L=sum(m=1, n, 2*2^valuation(m, 2)*polcoeff(log(SQ), m)*x^m)+x*O(x^n)); polcoeff(exp(L), n)}
CROSSREFS
KEYWORD
sign
AUTHOR
Paul D. Hanna, Jul 19 2009
STATUS
approved