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

A336873

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

Terms

    a(0) =1a(1) =3a(2) =73a(3) =36729a(4) =473940001

External references