a(n) = Sum_{k=0..n} G(n)/(G(k)*G(n-k)) where G(n) = Product_{k=0..n} k!.
A193520
a(n) = Sum_{k=0..n} G(n)/(G(k)*G(n-k)) where G(n) = Product_{k=0..n} k!.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =14a(4) =122a(5) =3122a(6) =260642a(7) =76214882a(8) =85552669442
External references
- oeis: A193520