a(n) = (-1)^n * n! * Sum_{k=0..floor(n/2)} n^(n-k) * Stirling1(n-k,k)/(n-k)!.

A362838

a(n) = (-1)^n * n! * Sum_{k=0..floor(n/2)} n^(n-k) * Stirling1(n-k,k)/(n-k)!.

Terms

    a(0) =1a(1) =0a(2) =4a(3) =27a(4) =704a(5) =26250a(6) =1573344a(7) =137145120a(8) =16494166016

External references