a(n) = [x^n] Product_{k=0..n} (1 + k*x)^4.

A384031

a(n) = [x^n] Product_{k=0..n} (1 + k*x)^4.

Terms

    a(0) =1a(1) =4a(2) =62a(3) =1680a(4) =65446a(5) =3334800a(6) =210218956a(7) =15803243456

External references