187524domain: NAppears in sequencesNumber of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 1), (-1, 0), (1, 0)}.at n=13A151261G.f. satisfies A(x) = (1 + x*A(x))^3 * (1 + x*A(x)^2).at n=6A274735