The challenges contained in Project Euler are mostly math oriented. Usually using a brute force algorithm will take a long time, while carefully exploiting the math proprieties of the problem will yield really performant algorithms.

- 67 - Maximum path sum II — solution
- 26 - Reciprocal cycles — solution
- 25 - 1000-digit Fibonacci number — solution
- 24 - Lexicographic permutations — solution
- 23 - Non-abundant sums — solution
- 22 - Names scores — solution
- 21 - Amicable numbers — solution
- 20 - Factorial digit sum — solution
- 19 - Counting Sundays — solution
- 18 - Maximum path sum I — solution
- 17 - Number letter counts — solution
- 16 - Power digit sum — solution
- 15 - Lattice paths — solution
- 14 - Longest Collatz sequence — solution
- 13 - Large sum — solution
- 12 - Highly divisible triangular number — solution
- 11 - Largest product in a grid — solution
- 10 - Summation of primes — solution
- 9 - Special Pythagorean triplet — solution
- 8 - Largest product in a series — solution
- 7 - 10001st prime — solution
- 6 - Sum square difference — solution
- 5 - Smallest multiple — solution
- 4 - Largest palindrome product — solution
- 3 - Largest prime factor — solution
- 2 - Even Fibonacci Numbers — solution
- 1 - Multiplies of 3 and 5 — solution