Type in the line size that you want; when asked whether you want to stop at an iteration, any answer other than "yes" will be taken to mean "no"; in other words, you can just press enter immediately until you get to an iteration you want to stop at. For sizes less than 4 (or if you don't want to watch the fractal draw itself), turbo mode is recommended.
For some reason, it stops drawing when "step_count" goes up to 200,000; if anyone can make this algorithm work longer (or make it take less time on the reiterations), feel free to remix this project. Also, for trivia, this fractal shows up in the original book of jurassic park (starting with iteration 3, which is the third time it pauses and asks whether you want to stop).