A182314 - OEIS

%I #7 Apr 24 2012 12:15:58

%S 1,1,2,13,174,4232,182382,14175046,2045373678,562261694364,

%T 299983681820740,314433086095052371,652379184283729238186,

%U 2691298717301069744228618,22133007749002207321732828222,363389633981231330655355989037627,11920985732676951145747564507103687806

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

%e G.f.: A(x) = 1 + x + 2*x^2 + 13*x^3 + 174*x^4 + 4232*x^5 + 182382*x^6 +...

%e Related expansions:

%e A(x)^2 = 1 + 2*x + 5*x^2 + 30*x^3 + 378*x^4 + 8864*x^5 + 374093*x^6 +...

%e A(A(x)^2 - 1) = 1 + 2*x + 13*x^2 + 174*x^3 + 4232*x^4 + 182382*x^5 +...

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

%o for(n=0,25,print1(a(n),", "))

%Y  Cf. A182224, A120970.

%K nonn

%O 0,3

%A _Paul D. Hanna_, Apr 24 2012