Bet you were expecting a lame tennis joke when you saw the title ... hey, waitaminute ....
Math and abstract art can go together sometime.
Don't be surprised if a portion of this gets used for a night sky in a future strip.
Or for celestrial railroad tracks.
If any further explanation is needed, this is a graph of all (x, y) values such that x and y are 2/3 of a Pythagorean Triple.