Prime spiral (also known as Ulam's spiral) implemented in Python using turtle
Saw this video by The Coding Train and thought it looked cool, and reasonable to implement myself.
Prime spiral with max value 3600 without path lines, and dot radius 10
Prime spiral with max value 10,000 without path lines, and dot radius 5
Prime spiral with max value 4000 with path lines, and dot radius 10
It is a bit slow but that's the nature of turtle
graphics.