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

A235327

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

Terms

    a(0) =1a(1) =1a(2) =6a(3) =69a(4) =1144a(5) =25045a(6) =708336a(7) =24564211a(8) =1020980640a(9) =49909891257

External references