556952

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=48A145876
• 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=51A145876
• Number of permutations of [n] having exactly three alternating descents.at n=6A302896
• Number of permutations of [n] having exactly six alternating descents.at n=3A302899