G.f.: A(x) = exp( Sum_{n>=1} 2*((3^n-1)/2)^(n-1)*x^n/n ).

A181316

G.f.: A(x) = exp( Sum_{n>=1} 2*((3^n-1)/2)^(n-1)*x^n/n ).

Terms

    a(0) =1a(1) =2a(2) =6a(3) =122a(4) =32242a(5) =85808250

External references