Ordered pairs of permutation functions on n elements where f(g(g(x))) = g(g(f(x))).

A239841

Ordered pairs of permutation functions on n elements where f(g(g(x))) = g(g(f(x))).

Terms

    a(0) =1a(1) =1a(2) =4a(3) =30a(4) =312a(5) =3720a(6) =64080a(7) =1305360a(8) =33949440a(9) =1019692800a(10) =36360576000

External references