One possible solution for Project Euler in language mathematica.
Inspired by Stone-zeng, I plan to do one question everyday to have fun and practise mma language. BUT according to my previous behaviour, this plan may be aborted in the near future. SO do not have any expectation on it.
See https://projecteuler.net/about to learn about this project.
Solutions given by Stone-zeng are copied from https://stone-zeng.github.io/.