204559349854domain: NAppears in sequencesTotal number of nodes in all self-avoiding planar walks starting at (0,0), ending at (n,0), not extending above the line (x,2x) or below the line (x,-2x), and using steps (0,1), (-1,1), and (1,-1) with the restriction that (-1,1) and (1,-1) are always immediately followed by (0,1).at n=23A328140