Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, down, up, down, down.

A177620

Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, down, up, down, down.

Terms

    a(0) =1a(1) =20a(2) =1668a(3) =359100a(4) =158300844a(5) =124353422844

External references