## Project Euler: Problem 35

The task in Problem 35 of Project Euler is: The number, 197, is called a circular prime because all rotations of the digits: 197, 971, and 719, are themselves prime. There are thirteen such primes below 100: 2, 3, 5, 7, 11, 13, 17, 31, 37, 71, 73, 79, and 97. How many circular primes [...]

## Project Euler: Problem 33

The task in Problem 33 of Project Euler is: The fraction is a curious fraction, as an inexperienced mathematician in attempting to simplify it may incorrectly believe that , which is correct, is obtained by cancelling the 9s. We shall consider fractions like, , to be trivial examples. There are exactly four non-trivial examples of [...]

## Project Euler: Problem 32

The task in Problem 32 of Project Euler is: We shall say that an -digit number is pandigital if it makes use of all the digits 1 to n exactly once; for example, the 5-digit number, 15234, is 1 through 5 pandigital. The product 7254 is unusual, as the identity, , containing multiplicand, multiplier, and [...]

## Project Euler: Problem 26

The task in Problem 26 of Project Euler is: Find the value of d < 1000 for which contains the longest recurring cycle in its decimal fraction part. How to solve Think about how you divide with pen and paper. How do you recognize that you have a cycle? You look at the rest. If [...]

## Project Euler: Problem 142

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. The motivation for starting Project Euler, and its continuation, [...]

## Community Chess

Community Chess is one of my projects. I can make something usefull and play a bit. This project has now an own URL: community-chess.com It’s a little bit crappy at the moment as I’ve just started studying, but I’ll fix that. If you like to help, please write me an Email (info@martin-thoma.de). Everybody can help. [...]

## Challenge Websites

Challenge websites are websites which offer many tasks to solve and a ranking system. If you solve the challenges, you get points and your rank increases. You don’t get anything else. No money, no price. Only the knowledge and the ranking. Which is enough in my opinion. It might sound strange to others, but its [...]