Desert Island Math, April 11, 2022 (Squares and Cubes)
I have made my “sandbox” in CoCalc (Sage) public. Here is the link. Get your own account by going to Cocalc.com, and then you can copy my file and modify it. When you go to the link, you get the latest version that I have made. This version has some code for exploring the sticky square, and for seeing which numbers can be written as the sum of two squares.
I did a program on October 28, 2020 on “Geometry and Number Theory” in which I presented a fun geometric proof of Fermat’s Christmas theorem. Here is a link for the video.