G.f. A(x) satisfies: A(x) = 1 / (1 - 2*x - x * A(2*x)).

A348903

G.f. A(x) satisfies: A(x) = 1 / (1 - 2*x - x * A(2*x)).

Terms

    a(0) =1a(1) =3a(2) =15a(3) =123a(4) =1623a(5) =35427a(6) =1349727a(7) =94653195a(8) =12690736167

External references