Number of permutations of [2n] having exactly n-1 alternating descents.

A302904

Number of permutations of [2n] having exactly n-1 alternating descents.

Terms

    a(0) =1a(1) =1a(2) =7a(3) =182a(4) =8699a(5) =704834a(6) =84889638a(7) =14322115212

External references