Number of pairs of functions f, g from a size n set into itself satisfying f(g(x)) = f(f(g(x))).
A239781
Number of pairs of functions f, g from a size n set into itself satisfying f(g(x)) = f(f(g(x))).
Terms
- a(0) =1a(1) =1a(2) =12a(3) =321a(4) =15280a(5) =1127745a(6) =118507536a(7) =16731979033
External references
- oeis: A239781