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

A383282

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

Terms

    a(0) =1a(1) =1a(2) =5a(3) =51a(4) =906a(5) =24690a(6) =956790a(7) =49993650a(8) =3387124440a(9) =288755250840

External references