379448391283domain: NAppears in sequencesNumber of self-avoiding planar walks starting at (0,0), ending at (n,0), remaining in the first quadrant and using steps (0,1), (1,0), (1,1), (-1,1), and (1,-1) with the restrictions that (0,1) and (1,-1) are never used above the diagonal and (1,0) and (-1,1) are never used below the diagonal and (1,1) can only be used below the diagonal.at n=21A303477