a(n) = (1/2)*(n+1)!*Sum_{k=0..floor(n/2)} n^(2k+1)/(2k+1)!.
A046706
a(n) = (1/2)*(n+1)!*Sum_{k=0..floor(n/2)} n^(2k+1)/(2k+1)!.
Terms
- a(0) =0a(1) =1a(2) =10a(3) =90a(4) =1392a(5) =18675a(6) =409104a(7) =7411348a(8) =209085952a(9) =4788571365a(10) =164757984000
External references
- oeis: A046706