Ask HN: Recommended MOOC courses for CS/Mathy SWE taking a year+ off

I am going to be taking a year+ off after 16 years of being a SWE. I am looking for a some very well done and interesting online classes, just for my own enjoyment and growth. I have been interested in more of the mathy parts of CS, algorithms, theory of computation, discrete math, graph theory, game theory, and behavioral economics. More recently, I've done a lot of applied machine learning at work and have an MS in CS with a focus in ML. Within or adjacent to these interests, I'd just like to take some good classes.