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

A302903

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

Terms

    a(0) =1a(1) =2a(2) =36a(3) =1196a(4) =76840a(5) =7570716a(6) =1085246904a(7) =211595659320

External references