a(n) = 2^(n-1)*binomial(2*n-1,n-1)^2.

A116421

a(n) = 2^(n-1)*binomial(2*n-1,n-1)^2.

Terms

    a(0) =0a(1) =1a(2) =18a(3) =400a(4) =9800a(5) =254016a(6) =6830208a(7) =188457984a(8) =5300380800a(9) =151289881600

External references