OFFSET
0,2
COMMENTS
LINKS
Paul D. Hanna, Table of n, a(n) for n = 0..10000 (terms 0..100 from Georg Fischer)
EXAMPLE
G.f.: A(q) = 1 + 3*q + 3*q^2 + 3*q^3 + 9*q^4 + 12*q^5 + 12*q^6 +...
log(A(q)) = 3*q - 3*q^2/2 + 9*q^3/3 + 9*q^4/4 - 12*q^5/5 + 45*q^6/6 - 18*q^7/7 +...
Compare to: q - q^2/2 + q^3/3 + 3*q^4/4 - 4*q^5/5 + 5*q^6/6 - 6*q^7/7 +...
which equals log( Sum_{n>=0} q^(n^2) ) as described by A162552.
PROG
(PARI) {a(n)=local(Q=sum(m=0, n, x^(m^2))+x*O(x^n), A); A=exp(sum(k=1, n, polcoeff(log(Q), k)*3*3^valuation(k, 3)*x^k)+x*O(x^n)); polcoeff(A, n)}
CROSSREFS
KEYWORD
sign
AUTHOR
Paul D. Hanna, Jul 21 2009
STATUS
approved