a(n) = Sum_{k=0..n} ((2k+1)*C(n,k)*C(n+k,k))^2, where C(n,k) denotes the binomial coefficient n!/(k!*(n-k)!).

A246461

a(n) = Sum_{k=0..n} ((2k+1)*C(n,k)*C(n+k,k))^2, where C(n,k) denotes the binomial coefficient n!/(k!*(n-k)!).

Terms

    a(0) =1a(1) =37a(2) =1225a(3) =43397a(4) =1563401a(5) =56309885a(6) =2020496185a(7) =72190600165

External references