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

A326274

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

Terms

    a(0) =1a(1) =4a(2) =64a(3) =1920a(4) =86464a(5) =5304320a(6) =418131456a(7) =40727959552

External references