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

A235328

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

Terms

    a(0) =1a(1) =1a(2) =6a(3) =69a(4) =1336a(5) =39145a(6) =1598256a(7) =85996561a(8) =5872177536a(9) =494848403793

External references