a(n) = n! * Sum_{k=0..floor(n/2)} k^n/k!.
A357191
a(n) = n! * Sum_{k=0..floor(n/2)} k^n/k!.
Terms
- a(0) =1a(1) =0a(2) =2a(3) =6a(4) =216a(5) =2040a(6) =111240a(7) =2164680a(8) =159391680a(9) =5247305280a(10) =491431600800
External references
- oeis: A357191