2220288domain: NAppears in sequencesE.g.f. satisfies: A'(x) = 1/(1 - x*A(x))^2 with A(0)=1.at n=8A144011Triangle read by rows, T(n,k) with n,k > 1, is the number of subsequences of length k over all permutations of [n], which are neither increasing or decreasing.at n=24A373766