A239760 - OEIS

A239760

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

%I #17 Nov 16 2016 05:45:05

%S 1,1,10,123,1984,38765,899856,24135055,734381824,24985937241,

%T 939674886400,38697245287811,1731506682516480,83631998873272837,

%U 4336190248653942784,240186479159794548375,14153996066789439471616,884109266328681103701425,58346867827408911965945856

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

%H David Einstein, <a href="/A239760/b239760.txt">Table of n, a(n) for n = 0..100</a>

%H David Einstein, <a href="https://github.com/deinst/oeis-function-identities/blob/master/Cyclic%20Count.ipynb">Sage notebook for A239760</a>

%Y Cf. A000248, A000949.

%K nonn

%O 0,3

%A _Chad Brewbaker_, Mar 26 2014

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

%E More terms from _David Einstein_, Nov 15 2016