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

A350595

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

Terms

    a(0) =1a(1) =0a(2) =6a(3) =1680a(4) =5562130a(5) =248832363780

External references