137779domain: NAppears in sequencesNumber of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, 0), (0, 1), (1, -1), (1, 1)}.at n=12A151409a(n) = 7*3^n - 2.at n=9A355492