I’ve been working steadily through Project Euler for the past couple years; about 2/3 finished. That’s introduced me to many fascinating parts of mathematics I

I’ve been working steadily through Project Euler for the past couple years; about 2/3 finished. That’s introduced me to many fascinating parts of mathematics I never studied as an undergrad, 40 years ago. Chromatic polynomials are one of the most delightful areas I’ve been introduced to. Such a pretty mix of graph theory and generating functions.