Number of ordered pairs of endofunctions (f,g) on a set of n elements satisfying g(f(x)) = f(f(f(x))).

A239750

Number of ordered pairs of endofunctions (f,g) on a set of n elements satisfying g(f(x)) = f(f(f(x))).

Terms

    a(0) =1a(1) =1a(2) =6a(3) =87a(4) =2200a(5) =84245a(6) =4492656a(7) =315937195a(8) =28186856832

External references