704834

Appears in sequences

• Triangle read by rows: T(n,k) is the number of permutations of [n] having k-1 alternating descents (1<=k<=n). The index i is an alternating descent of a permutation p if either i is odd and p(i)>p(i+1), or i is even and p(i)<p(i+1).at n=49A145876
• Triangle read by rows: T(n,k) is the number of permutations of [n] having k-1 alternating descents (1<=k<=n). The index i is an alternating descent of a permutation p if either i is odd and p(i)>p(i+1), or i is even and p(i)<p(i+1).at n=50A145876
• Number of permutations of [n] having exactly four alternating descents.at n=5A302897
• Number of permutations of [n] having exactly five alternating descents.at n=4A302898
• Number of permutations of [2n] having exactly n-1 alternating descents.at n=5A302904
• Number of permutations of [n] having exactly ceiling(n/2)-1 alternating descents.at n=10A302905