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

A239782

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

Terms

    a(0) =1a(1) =1a(2) =14a(3) =321a(4) =12256a(5) =682985a(6) =52551216a(7) =5333977789

External references