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

A177643

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

Terms

    a(0) =1a(1) =60a(2) =21524a(3) =26227974a(4) =81550349446

External references