Number of pairs of functions f, g from a size n set into itself satisfying f(f(g(x))) = f(f(x)).
A239775
Number of pairs of functions f, g from a size n set into itself satisfying f(f(g(x))) = f(f(x)).
Terms
- a(0) =1a(1) =1a(2) =10a(3) =297a(4) =13264a(5) =851325a(6) =74078496a(7) =8325102331
External references
- oeis: A239775