Number of permutations sigma of [n] such that all values k * sigma(k) for 1 <= k <= n are pairwise distinct.
A333083
Number of permutations sigma of [n] such that all values k * sigma(k) for 1 <= k <= n are pairwise distinct.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =3a(4) =13a(5) =67a(6) =305a(7) =2359a(8) =16495a(9) =141643a(10) =1273691a(11) =15580299a(12) =152788607a(13) =2206382433a(14) =28916044241a(15) =399450183613
External references
- oeis: A333083