a(n) = Sum_{i=0..n} Sum_{j=0..n} Sum_{k=0..n} Sum_{l=0..n} Sum_{m=0..n} (-1)^(i+j+k+l+m) * (i+j+k+l+m)!/(i!*j!*k!*l!*m!).

A308325

a(n) = Sum_{i=0..n} Sum_{j=0..n} Sum_{k=0..n} Sum_{l=0..n} Sum_{m=0..n} (-1)^(i+j+k+l+m) * (i+j+k+l+m)!/(i!*j!*k!*l!*m!).

Terms

    a(0) =1a(1) =-44a(2) =44121a(3) =-66211704a(4) =120965241901

External references