I remember doing combinatorics puzzles and number theory exercises in platforms like Brilliant when I had a bit of free time. All the while learning something. But the last time I tried Brilliant I did not enjoy it as much and I can’t afford it not anyway.
Does anyone have any recommendations of websites (or webrings), apps or games about or that touch on:
- combinatorics puzzles
- modular arithmetic puzzles
- concepts or exercises of number theory
Also shout out to cryptogram/cipher style games, which i see as reasonably mathematical
https://cyphrgame.com/ https://decipher.wtf/ https://cryptograms.puzzlebaron.com/play.php
I think the puzzle baron one might be dominated by bots because it has solve times of 1 second listed when i do it.