Number of permutations of n distinct letters (ABCD...) each of which appears thrice with two fixed points.
A124042
Number of permutations of n distinct letters (ABCD...) each of which appears thrice with two fixed points.
Terms
- a(0) =0a(1) =9a(2) =378a(3) =84510a(4) =38358540a(5) =31234760055
External references
- oeis: A124042