Number of endofunctions f on [2n] satisfying f^3(i) = i for all i in [n].
A245959
Number of endofunctions f on [2n] satisfying f^3(i) = i for all i in [n].
Terms
- a(0) =1a(1) =2a(2) =36a(3) =1440a(4) =84624a(5) =7675200a(6) =962250624a(7) =151851992544
External references
- oeis: A245959