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%I #4 Apr 30 2014 01:37:09
%S 1,-506,-15625,-89206,-271151,-420838,-638066,0,56446,2172742,1771561,
%T 5443200,0,7082714,-4570773,-98282,-13055614,0,-29937600,4072822,
%U -26439842,0,0,26266966,-24137569,70761600,38871506,7906250,52240606,56926298,-29158919
%N Expansion of f(-q)^2*R(q) in powers of q.
%C f(-q) (g.f. A010815) and R(q) (g.f. A013973) are Ramanujan q-series.
%H S. R. Finch, <a href="http://arXiv.org/abs/math.NT/0701251">Powers of Euler's q-Series</a>, (arXiv:math.NT/0701251).
%o (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))}
%K sign
%O 0,2
%A _Michael Somos_, Aug 28 2006