Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, up, up, up.
A177646
Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, up, up, up.
Terms
- a(0) =1a(1) =1a(2) =70a(3) =34650a(4) =63063000a(5) =302857024681
External references
- oeis: A177646