A137983 - OEIS

A137983

G.f.: A(x) = 1/(1 - x*A_0(x)) where A_0(x) = 1/(1 - 2x*A_1(x)^(1/2)) such that A_{n-1}(x) = 1/(1 - 2^n*x*[A_{n}(x)]^(1/2^n)) for n>=1 with A_0(x) equal to the g.f. of A137984.

%I #2 Mar 30 2012 18:37:09

%S 1,1,3,13,71,469,3723,36005,436547,6899269,148118063,4468393661,

%T 193343082863,12098043923845,1095808155971903,143385496616202557,

%U 27027137980334917335,7318231233568088061141,2839533242388092176367563

%N G.f.: A(x) = 1/(1 - x*A_0(x)) where A_0(x) = 1/(1 - 2x*A_1(x)^(1/2)) such that A_{n-1}(x) = 1/(1 - 2^n*x*[A_{n}(x)]^(1/2^n)) for n>=1 with A_0(x) equal to the g.f. of A137984.

%e See examples given in A137984.

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

%Y Cf. A137984.

%K nonn

%O 0,3

%A _Paul D. Hanna_, Feb 27 2008