A239763 Number of pairs of functions (f,g) from a set of n elements into itself satisfying f(f(x)) = f(g(x)).

1, 1, 10, 171, 4600, 168285, 7988736, 472245991

Offset

0,3

Links

Table of n, a(n) for n=0..7.

Crossrefs

Cf. A181162.

Sequence in context: A187204 A346458 A133273 * A112703 A132676 A270958

Adjacent sequences: A239760 A239761 A239762 * A239764 A239765 A239766

Keyword

nonn,more

Author

Chad Brewbaker, Mar 26 2014

Extensions

a(6)-a(7) from Giovanni Resta, Mar 28 2014

Status

approved