E.g.f.: A(x) = Product_{n>=1} (1 + 3*x^n/n)^n.

A182966

E.g.f.: A(x) = Product_{n>=1} (1 + 3*x^n/n)^n.

Terms

    a(0) =1a(1) =3a(2) =6a(3) =72a(4) =342a(5) =3330a(6) =36720a(7) =366660a(8) =4974480a(9) =67178160a(10) =1043189280a(11) =16836906240a(12) =303306806880

External references