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Number of pairs of functions (f,g) from a set of n elements into itself satisfying f(f(g(x))) = g(g(x)).
0

%I #9 Jul 18 2014 12:37:18

%S 1,1,8,129,3616,151845,8864496,682005919

%N Number of pairs of functions (f,g) from a set of n elements into itself satisfying f(f(g(x))) = g(g(x)).

%Y Cf. A000248, A000949.

%K nonn,more

%O 0,3

%A _Chad Brewbaker_, Mar 26 2014

%E a(6)-a(7) from _Giovanni Resta_, Mar 28 2014