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.
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.
Terms
- a(0) =6a(1) =120a(2) =2160a(3) =41160a(4) =860160a(5) =19840464a(6) =504000000a(7) =14030763120a(8) =425681879040
External references
- oeis: A065888