a(n) = Sum_{k=0..n} (k!)^(n-k).
A056162
a(n) = Sum_{k=0..n} (k!)^(n-k).
Terms
- a(0) =1a(1) =2a(2) =3a(3) =5a(4) =13a(5) =71a(6) =931a(7) =30275a(8) =2591059a(9) =614059331a(10) =423463272451
External references
- oeis: A056162
A056162
a(n) = Sum_{k=0..n} (k!)^(n-k).