a(n) = n! * Sum_{k=0..floor(n/2)} (n - 2*k)^k/(n - 2*k)!.
A356628
a(n) = n! * Sum_{k=0..floor(n/2)} (n - 2*k)^k/(n - 2*k)!.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =7a(4) =25a(5) =181a(6) =1561a(7) =12811a(8) =188497a(9) =2071945a(10) =38889361a(11) =620762671a(12) =12917838121a(13) =291278938237
External references
- oeis: A356628