Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, up.
A177637
Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, up.
Terms
- a(0) =1a(1) =1a(2) =70a(3) =20251a(4) =19387201a(5) =47213021620
External references
- oeis: A177637