Coefficient of x^(2^(n-1)) in the n-th self-composition of (x+x^2) for n>=1.

A122894

Coefficient of x^(2^(n-1)) in the n-th self-composition of (x+x^2) for n>=1.

Terms

    a(0) =1a(1) =2a(2) =9a(3) =258a(4) =293685a(5) =531124770570

External references