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

A036916

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

Terms

    a(0) =1a(1) =5a(2) =53a(3) =761a(4) =12661a(5) =229705a(6) =4410665a(7) =88127485a(8) =1813270645a(9) =38158684745a(10) =817458330553

External references