Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, down, up, down.

A177649

Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, down, up, down.

Terms

    a(0) =1a(1) =70a(2) =31830a(3) =50395146a(4) =205822250572

External references