Project Euler is a fun site but what starts off as programming puzzles quickly becomes math puzzles. Most seem to be plain impossible no matter how good a programmer you are if you simply don't know the particular math needed to solve the puzzle.
OP here. I agree - I'm exploring puzzles which are the most useful to programmers, and what makes them great. For example: https://projecteuler.net/problem=8 can be solved in a simple way which is very clear using functional programming (Linq in C#). Very enjoyable.
However some others eg Euler11 felt like hard work.
I've done the first 50 or 60 questions and got that far using programming (without the interest in recreational math). In general I really enjoy these puzzles.
