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

A119394

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

Terms

    a(0) =1a(1) =1a(2) =-3a(3) =19a(4) =-191a(5) =2301a(6) =-5579a(7) =-2972633a(8) =365848449a(9) =-41439009671

External references