a(n) = Sum_{k=0..n} n^k * binomial(k+n,k).

A368489

a(n) = Sum_{k=0..n} n^k * binomial(k+n,k).

Terms

    a(0) =1a(1) =3a(2) =31a(3) =643a(4) =20421a(5) =873806a(6) =46994011a(7) =3042431715a(8) =230249448841

External references