A065888 - cp's OEIS frontend

A065888 a(n) = number of endofunctions on [n] with a 4-cycle a->b->c->d->a and for any x in [n], some iterate f^k(x) = a.

n	a(n)
4	6
5	120
6	2160
7	41160
8	860160
9	19840464
10	504000000
11	14030763120
12	425681879040
13	13997939172360
14	496360987938816
15	18891066796875000
16	768426686420090880
17	33279382190563948320
18	1529238539734890577920
19	74326797938267012471904

[6, 120, 2160, 41160, 860160, 19840464, 504000000, 14030763120, 425681879040, 13997939172360, 496360987938816, 18891066796875000, 768426686420090880, 33279382190563948320, 1529238539734890577920, 74326797938267012471904]

cp's OEIS Frontend

A065888 a(n) = number of endofunctions on [n] with a 4-cycle a->b->c->d->a and for any x in [n], some iterate f^k(x) = a.

Table of values

List of values