a(n) = Sum_{k=0..n} (-1)^(n - k) * binomial(n,k) * binomial(n+k,k) * n^k.

A331657

a(n) = Sum_{k=0..n} (-1)^(n - k) * binomial(n,k) * binomial(n+k,k) * n^k.

Terms

    a(0) =1a(1) =1a(2) =13a(3) =305a(4) =10321a(5) =458649a(6) =25289461a(7) =1666406209a(8) =127779121345

External references