Lattice points on ellipses
How weird ?
These growing ellipses have all the Z² lattice points on their boundary. Move the slider k and observe the equation of the red ellipse. It's always x²-xy+y²=n, but not for every integer n...
I tried to reproduce a somewhat surprising result exposed in this awesome video by Edmund Harriss ans Pierre Arnoux. Next step is to make the points rotate.
Animated GIF extracted from the video.
