Number of functions on a finite set that are not obtainable by any composition power (excluding identity as power).
A163947
Number of functions on a finite set that are not obtainable by any composition power (excluding identity as power).
Terms
- a(0) =0a(1) =0a(2) =6a(3) =84a(4) =1400a(5) =25590a(6) =516432
External references
- oeis: A163947