1365354

Appears in sequences

• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k doubledescents (0 <= k <= n-2). We say that i is a doubledescent (also called a double fall) of a permutation p if p(i) > p(i+1) > p(i+2).at n=39A162975
• Number of permutations of [n] having exactly one doubledescent.at n=10A274997