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%I #5 Mar 30 2012 18:37:27
%S 1,1,1,1,2,3,6,9,15,22,34,50,78,119,188,295,466,728,1134,1742,2659,
%T 4018,6037,9018,13443,19993,29749,44274,65976,98372,146781,218922,
%U 326290,485476,720817,1067293,1575713,2318852,3401845,4975174,7255629,10553845,15317091
%N G.f.: A(x) = Sum_{n>=0} x^(n^2) / Product_{k=1..n} (1 - x^k)^n.
%e G.f.: A(x) = 1 + x + x^2 + x^3 + 2*x^4 + 3*x^5 + 6*x^6 + 9*x^7 +...
%e where:
%e A(x) = 1 + x/(1-x) + x^4/((1-x)*(1-x^2))^2 + x^9/((1-x)*(1-x^2)*(1-x^3))^3 + x^16/((1-x)*(1-x^2)*(1-x^3)*(1-x^4))^4 +...
%o (PARI) {a(n)=local(A=1);polcoeff(sum(m=0,n,x^(m^2)/prod(k=1,m,1-x^k +x*O(x^n))^m),n)}
%K nonn
%O 0,5
%A _Paul D. Hanna_, Jul 17 2011
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