Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, down, up, up, down.
A177622
Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, down, up, up, down.
Terms
- a(0) =1a(1) =20a(2) =1662a(3) =353608a(4) =153356948a(5) =118150658380
External references
- oeis: A177622