a(n) = Sum_{k=0..n} binomial(n,k)^2*binomial(n-k,k)^2*(-324)^k.

A179536

a(n) = Sum_{k=0..n} binomial(n,k)^2*binomial(n-k,k)^2*(-324)^k.

Terms

    a(0) =1a(1) =1a(2) =-1295a(3) =-11663a(4) =3732481a(5) =94348801a(6) =-12754875599a(7) =-662010720335

External references