Choosing specific numbers using lists and modulo

The entire explanation of how to use this calculator and understand it is in the link!

Sorting Numbers

If anyone knows any way to get rid of the undefined placeholder and make it just empty, feel free to show me and/or link a graph to it! If you find a better way to do this also tell me.

See if this fits your needs.

Here’s a different way. Basically taking the list n, but only keeping those elements with remainder, 0. Then, down below, using L_2 instead of Y for the purple points. You could easily make a second list if you wanted another set of points a different color. L_3= n [mod(n,d)>0]