E.g.f.: Sum_{n>=0} 4^n * (exp(n*x) - 1)^n / n!.

A326288

E.g.f.: Sum_{n>=0} 4^n * (exp(n*x) - 1)^n / n!.

Terms

    a(0) =1a(1) =4a(2) =68a(3) =2116a(4) =98436a(5) =6217924a(6) =503491204a(7) =50282169284

External references