%I A139632
%S A139632 1,1,0,1,1,0,0,1,1,1,1,1,2,1,1,1,2,2,1,2,3,3,2,3,4,3,2,4,5,4,4,5,6,6,5,
%T A139632 6,8,7,6,8,11,10,8,11,13,11,10,13,16,15,14,17,20,18,17,20,24,23,21,25,
%U A139632 31,29,26,32,37,34,32,39,44,42,41,47,54,52,49,56,64,62,59,68,79,77,72
%N A139632 Expansion of chi(q) * chi(-q^5) in powers of q where chi() is a Ramanujan 
               theta function.
%F A139632 Expansion of q^(1/4) * eta(q^2)^2 * eta(q^5) / (eta(q) * eta(q^4) * eta(q^10)) 
               in powers of q.
%F A139632 G.f. is a period 1 Fourier series which satisfies f(-1 / (640 t)) = 2^(1/
               2) g(t) where q = exp(2 pi i t) and g() is g.f. for A139631.
%F A139632 G.f.: Product_{k>0} (1 + x^k) / ((1 + x^(2*k)) * (1 + x^(5*k))).
%e A139632 1/q + q^3 + q^11 + q^15 + q^27 + q^31 + q^35 + q^39 + q^43 + 2*q^47 + 
               ...
%o A139632 (PARI) {a(n) = local(A); if( n<0, 0, A = x * O(x^n); polcoeff( eta(x^2 
               + A)^2 * eta(x^5 + A) / eta(x + A) / eta(x^4 + A) / eta(x^10 + A), 
               n))}
%Y A139632 A139631(n) = a(2*n).
%Y A139632 Sequence in context: A086995 A135230 A117957 this_sequence A145704 A145705 
               A145702
%Y A139632 Adjacent sequences: A139629 A139630 A139631 this_sequence A139633 A139634 
               A139635
%K A139632 nonn
%O A139632 0,13
%A A139632 Michael Somos, Apr 27 2008