Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, up, down, down, down.
A177624
Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, up, down, down, down.
Terms
- a(0) =1a(1) =20a(2) =1680a(3) =365640a(4) =163278207a(5) =130045765680
External references
- oeis: A177624