The number of functions on a finite set that are obtainable by a composition power (excluding identity as power).
A163948
The number of functions on a finite set that are obtainable by a composition power (excluding identity as power).
Terms
- a(0) =1a(1) =4a(2) =21a(3) =172a(4) =1725a(5) =21066a(6) =307111
External references
- oeis: A163948