Bilinear Interferometry with numbers

move your mouse to hover a couple of numbers (x,y). It then compute v=i*i*i+j*j*j. grayscale relates to how close v is to previous/next int square numbers (ie how 29 is close to 25=5*5 and 36=6*6). If it's close to previous square I set it darker, if it's closer to next square I set it brighter