A235325 Number of ordered pairs of endofunctions f,g on a set of n elements satisfying f(f(x)) = g(g(g(x))).

1, 1, 4, 51, 1072, 31845, 1292616, 68464207, 4555593904, 369790197705

Offset

0,3

Links

Table of n, a(n) for n=0..9.

Crossrefs

Cf. A000248, A000949.

Sequence in context: A343572 A336608 A349653 * A230401 A293075 A300732

Adjacent sequences: A235322 A235323 A235324 * A235326 A235327 A235328

Keyword

nonn,more

Author

Chad Brewbaker, Mar 26 2014

Extensions

a(6)-a(7) from Giovanni Resta, Mar 26 2014

a(8)-a(9) from Giovanni Resta, Mar 28 2014

Status

approved