Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, down, up, up, up.
A177582
Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, down, up, up, up.
Terms
- a(0) =1a(1) =6a(2) =90a(3) =2510a(4) =112020a(5) =7307874a(6) =655845094a(7) =77496572328
External references
- oeis: A177582