Number of walks of length n on the square lattice (with steps N, E, S, W) that start at (0,0) and avoid the West quadrant {(i,j): i < -|j|}.

A260153

Number of walks of length n on the square lattice (with steps N, E, S, W) that start at (0,0) and avoid the West quadrant {(i,j): i < -|j|}.