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%I #2 Mar 30 2012 18:37:10
%S 1,1,4,26,202,1786,17296,179826,1980484,22895120,276005616,3452880648,
%T 44660161656,595491975516,8166748417744,114983040461254,
%U 1659471907641924,24519436191927936,370506958317854776
%N G.f. satisfies: A(x) = x + A(A(A(A(x))^2)).
%F G.f. satisfies: A( x - A(A(A(x)^2)) ) = x.
%e G.f.: A(x) = x + x^2 + 4*x^3 + 26*x^4 + 202*x^5 + 1786*x^6 + 17296*x^7 +...
%e Related expansions:
%e A(A(x)) = x + 2*x^2 + 10*x^3 + 73*x^4 + 628*x^5 + 6038*x^6 + 62896*x^7 +...
%e A(A(A(x))) = x + 3*x^2 + 18*x^3 + 147*x^4 + 1392*x^5 + 14544*x^6 +...
%e A(A(A(A(x)))) = x + 4*x^2 + 20*x^3 + 122*x^4 + 820*x^5 + 5838*x^6 +...
%e A(A(A(A(x))^2)) = x^2 + 4*x^3 + 26*x^4 + 202*x^5 + 1786*x^6 +...
%e The series reversion of A(x) = x - A(A(A(x)^2)), where
%e A(A(A(x)^2)) = x^2 + 2*x^3 + 11*x^4 + 68*x^5 + 526*x^6 + 4556*x^7 +...
%o (PARI) {a(n)=local(A=x+x^2);for(i=1,n,A=x+subst(A,x,subst(A,x,subst(A^2,x,A+x*O(x^n)))));polcoeff(A,n)}
%Y Cf. A141380, A141382, A141383; A141371.
%K nonn
%O 1,3
%A _Paul D. Hanna_, Jun 28 2008