Number of permutations of [n] having exactly four alternating descents.
A302897
Number of permutations of [n] having exactly four alternating descents.
Terms
- a(0) =16a(1) =117a(2) =1056a(3) =8699a(4) =76840a(5) =704834a(6) =6847224a(7) =70145634a(8) =758805360a(9) =8650769675a(10) =103790273632
External references
- oeis: A302897