Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, up, up, up, up.
A177588
Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, up, up, up, up.
Terms
- a(0) =1a(1) =6a(2) =90a(3) =2520a(4) =113160a(5) =7441949a(6) =674077493a(7) =80453033424
External references
- oeis: A177588