Number of permutations of [n] having exactly two alternating descents.

A302895

Number of permutations of [n] having exactly two alternating descents.

Terms

    a(0) =2a(1) =7a(2) =36a(3) =182a(4) =1056a(5) =6669a(6) =46348a(7) =350240a(8) =2866632a(9) =25260211a(10) =238550196a(11) =2403846954a(12) =25749417440a(13) =292191829273

External references