Number of pairs of functions (f, g) on a set of n elements into itself satisfying f(g(x)) = f(x).

A239761

Number of pairs of functions (f, g) on a set of n elements into itself satisfying f(g(x)) = f(x).

Terms

    a(0) =1a(1) =1a(2) =10a(3) =159a(4) =3496a(5) =98345a(6) =3373056a(7) =136535455a(8) =6371523712a(9) =336784920849

External references