a(n) = n! * Sum_{k=0..floor(n/2)} (n - 2*k)^(2*k)/(n - 2*k)!.
A357146
a(n) = n! * Sum_{k=0..floor(n/2)} (n - 2*k)^(2*k)/(n - 2*k)!.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =7a(4) =49a(5) =301a(6) =6241a(7) =74131a(8) =1722337a(9) =46346329a(10) =1090339201a(11) =48905462431
External references
- oeis: A357146