a(n) = Sum_{k = 0..n-1} binomial(n,k)^2*binomial(n+k,k)*binomial(n+k-1,k).

A361712

a(n) = Sum_{k = 0..n-1} binomial(n,k)^2*binomial(n+k,k)*binomial(n+k-1,k).

Terms

    a(0) =0a(1) =1a(2) =25a(3) =649a(4) =16921a(5) =448751a(6) =12160177a(7) =336745053a(8) =9513822745a(9) =273585035755

External references