A122267 Expansion of f(-q)^2*R(q) in powers of q.

1, -506, -15625, -89206, -271151, -420838, -638066, 0, 56446, 2172742, 1771561, 5443200, 0, 7082714, -4570773, -98282, -13055614, 0, -29937600, 4072822, -26439842, 0, 0, 26266966, -24137569, 70761600, 38871506, 7906250, 52240606, 56926298, -29158919

Offset

0,2

Comments

f(-q) (g.f. A010815) and R(q) (g.f. A013973) are Ramanujan q-series.

Links

Table of n, a(n) for n=0..30.

S. R. Finch, Powers of Euler's q-Series, (arXiv:math.NT/0701251).

Prog

(PARI) {a(n)=local(A); if(n<0, 0, A=x*O(x^n); polcoeff( eta(x+A)^2*sum(k=1, n, -504*sigma(k, 5)*x^k, 1+A), n))}

Crossrefs

Sequence in context: A204954 A204947 A295992 * A204946 A023913 A035848

Adjacent sequences: A122264 A122265 A122266 * A122268 A122269 A122270

Keyword

sign

Author

Michael Somos, Aug 28 2006

Status

approved