Factors: The numbers from 1 to 500 are plotted horizontally across the top row. Along each vertical column, if N divides the number X (represented here by distance across the top row) evenly (that is, if N is a factor of X), then the pixel N pixels down from the top is black.
Prime Factors: The same general principle as above, but in this image, only the prime factors are shown.
Blue Over Yellow: Basically, a combination of the previous two images. Numbers from 1 to 250 are plotted horizontally, and factors are plotted vertically. If a factor is prime, the little square representing it is blue, otherwise, it’s yellow.
That tantalizing structure is still just slightly out of reach…Oh well, back to work!