Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, down, down, down.
A177647
Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, down, down, down.
Terms
- a(0) =1a(1) =1a(2) =70a(3) =34650a(4) =63063000a(5) =303526299000
External references
- oeis: A177647