%I #11 Mar 28 2014 00:28:25
%S 1,1,2,6,48,360,2880,20160,241920,3265920
%N Number of ordered pairs of permutation functions f,g on a size n set where f(g(g(x))) = g(f(f(x))).
%Y Cf. A000012, A000085, A000142, A088311, A053529, A001044.
%K nonn,more
%O 0,3
%A _Chad Brewbaker_, Mar 27 2014
%E a(8)-a(9) from _Giovanni Resta_, Mar 27 2014