Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, down, up, down, down.
A177661
Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, down, up, down, down.
Terms
- a(0) =1a(1) =70a(2) =34302a(3) =60601152a(4) =281381782044
External references
- oeis: A177661