Table of Contents
Overview: Problem 172
How many 18-digit numbers \(n\) (without leading zeros) are there such that no digit occurs more than three times in \(n\)?
Link to Project Euler Problem 172
Background
Project Euler Problem 172 is your classic Project Euler problem: short, simple, and overwhelmingly complicated.
To nail this one, it's important to start simple - very simple. What I'll do is walk through the process of …