Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, up, up.
A177644
Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, up, up.
Terms
- a(0) =1a(1) =70a(2) =29874a(3) =43724128a(4) =163394718481
External references
- oeis: A177644