a(n) = [x^n] Product_{k=1..n} (1 + k*x)^n.

A351507

a(n) = [x^n] Product_{k=1..n} (1 + k*x)^n.

Terms

    a(0) =1a(1) =1a(2) =13a(3) =630a(4) =65446a(5) =11732175a(6) =3222746276

External references