a(n) = (2n)! * Sum_{k=0..n} (-1)^k * binomial(n,k) / (n+k)!.
A006902
a(n) = (2n)! * Sum_{k=0..n} (-1)^k * binomial(n,k) / (n+k)!.
Terms
- a(0) =1a(1) =1a(2) =5a(3) =47a(4) =641a(5) =11389a(6) =248749a(7) =6439075a(8) =192621953a(9) =6536413529a(10) =248040482741
External references
- oeis: A006902