It's Cellular Autometa Rule 15, with some of the options changed to be random. (ie: "be the opposite of the cell to your top left"). This generates unbroken con

It's Cellular Autometa Rule 15, with some of the options changed to be random. (ie: "be the opposite of the cell to your top left"). This generates unbroken continuous wiggly lines varying between horizontal, diagonal and vertical within one quadrant. Other than the random elements, there's one exception: 11001 -> 0, which directly leads to a nice downward branching structure.