What is Project Euler? (https://projecteuler.net/): Project Euler is a series of challenging mathematical/computer programming problems that will require more than just mathematical insights to solve. Although mathematics will help you arrive at elegant and efficient methods, the use of a computer and programming skills will be required to solve most problems.
Who is Euler? https://en.wikipedia.org/wiki/Leonhard_Euler
You are encouraged to try and solve the problems by yourself before looking up into my solutions :)