a(n) = Sum_{k = 0..n} k * binomial(n,k)^2 * binomial(n+k,k)^2.

A357510

a(n) = Sum_{k = 0..n} k * binomial(n,k)^2 * binomial(n+k,k)^2.

Terms

    a(0) =0a(1) =4a(2) =108a(3) =3144a(4) =95000a(5) =2935020a(6) =92054340a(7) =2918972560a(8) =93330811440

External references