I wish he would go back to his fantastic youtube channel. I wonder if he ever said why he stopped posting. I also downloaded the entire thing in case it disappeared one day, some really good stuff there... https://www.youtube.com/@codingmath/videos
I still have one of his books on the shelf "Foundation ActionScript Animation: Making Things Move!". Lots of great explainations on the math behind animation and its easy to ignore the Flash specific stuff.
Another good book (if that's still anyone's thing) on tweening is the freely available part Dynamic Visuals of Robert Penner's book Programming Macromedia Flash:
