G.f.: A(x) = x + x*ITERATE^2(x + x*ITERATE^4(x + x*ITERATE^6(x + x*ITERATE^8(x + ...)))), where ITERATE^n(F(x)) denotes the n-th iteration of F(x), and the nesting of even iterations continue indefinitely.

A205320

G.f.: A(x) = x + x*ITERATE^2(x + x*ITERATE^4(x + x*ITERATE^6(x + x*ITERATE^8(x + ...)))), where ITERATE^n(F(x)) denotes the n-th iteration of F(x), and the nesting of even iterations continue indefinitely.