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%I #5 Mar 30 2012 18:37:27
%S 1,1,2,6,35,394,8804,397482,35759656,6485002635,2338622693988,
%T 1698239604693650,2450945990748440102,7121092086085582889354,
%U 41114705331946969977079884,477857552284771772990908082576
%N G.f.: A(x) = Sum_{n>=0} x^n / Product_{k=1..n} (1 - 4^(n-k)*x^k).
%F G.f. satisfies: A(4*x) = Sum_{n>=0} 4^n*x^n/Product_{k=1..n} (1-4^n*x^k).
%e G.f.: A(x) = 1 + x + 2*x^2 + 6*x^3 + 35*x^4 + 394*x^5 + 8804*x^6 +...
%e where:
%e A(x) = 1 + x/(1-x) + x^2/((1-4*x)*(1-x^2)) + x^3/((1-16*x)*(1-4*x^2)*(1-x^3)) + x^4/((1-64*x)*(1-16*x^2)*(1-4*x^3)*(1-x^4)) +...
%o (PARI) {a(n)=local(A=1);polcoeff(sum(m=0,n,x^m/prod(k=1,m,1-4^(m-k)*x^k +x*O(x^n))),n)}
%Y Cf. A193188, A193189, A193191.
%K nonn
%O 0,3
%A _Paul D. Hanna_, Jul 17 2011
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