281271domain: NAppears in sequencesNumber of nX6 0..2 arrays with antidiagonals unimodal and rows and diagonals nondecreasing.at n=4A223997Number of 5Xn 0..2 arrays with antidiagonals unimodal and rows and diagonals nondecreasing.at n=5A224003G.f. A(x) satisfies: A(x) = 1 + x * A(x/(1 - 2*x)) / (1 - 2*x)^2.at n=8A351756