Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, up, down, up, up, up.
A177633
Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, up, down, up, up, up.
Terms
- a(0) =1a(1) =20a(2) =1680a(3) =368168a(4) =166221670a(5) =134195139015
External references
- oeis: A177633