G.f.: A(x) = 1+x*(1+x*(1+x*(...(1+x*(...)^(-2^n) )...)^-4)^-2)^-1.

A121588

G.f.: A(x) = 1+x*(1+x*(1+x*(...(1+x*(...)^(-2^n) )...)^-4)^-2)^-1.

Terms

    a(0) =1a(1) =1a(2) =-1a(3) =3a(4) =-16a(5) =145a(6) =-2347a(7) =72498a(8) =-4459887a(9) =554300965a(10) =-139235329270

External references