274537

Appears in sequences

• Number of pairs of nested Dyck paths from (0,0) to (n,n) such that the upper path only touches the diagonal at its endpoints.at n=8A355281
• Number A(n,k) of k-tuples (p_1, p_2, ..., p_k) of Dyck paths of semilength n, such that each p_i is never below p_{i-1} and the upper path p_k only touches the x-axis at its endpoints; square array A(n,k), n>=0, k>=0, read by antidiagonals.at n=63A378112