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 A168603 G.f. satisfies: A(x) = 1 + x*A(x)^2*A(2x)^2. 1

%I

%S 1,1,6,73,1578,60582,4276284,574950725,150783454338,78124426877002,

%T 80472666325118724,165293072210433580170,678034405564452384600036,

%U 5558530569192415381768200652,91104334435045362173635840712184

%N G.f. satisfies: A(x) = 1 + x*A(x)^2*A(2x)^2.

%e G.f.: A(x) = 1 + x + 6*x^2 + 73*x^3 + 1578*x^4 + 60582*x^5 +...

%e A(x)^2 = 1 + 2*x + 13*x^2 + 158*x^3 + 3338*x^4 + 125196*x^5 +...

%o (PARI) {a(n)=local(A=1+x+x*O(x^n)); for(i=0, n, A=1+x*A^2*subst(A, x, 2*x)^2 ); polcoeff(A, n)}

%Y Cf. A168602.

%K nonn

%O 0,3

%A _Paul D. Hanna_, Dec 05 2009

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