Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, up, down, up, down.
A177666
Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, up, down, up, down.
Terms
- a(0) =1a(1) =68a(2) =31212a(3) =50966304a(4) =217643900486
External references
- oeis: A177666