Hey, welcome to Nim, If you like learning with mathematical challenges, I started Nim and many other languages with Project Euler, which gives you small mathematical challenges for your programming languages craving.
[https://projecteuler.net](https://projecteuler.net)/ Here are my [solutions to the first 10 problems](https://github.com/mratsim/nim-projecteuler) including a [fast packed bitarray-based Sieve of Eratosthenes](https://github.com/mratsim/nim-projecteuler/blob/master/lib_euler_primes.nim#L160) with OpenMP parallel loop. I compared it to Rosettacode sieves and primesieve/primegen (C/C++) and various Haskell solutions and even Sieve of Atkins, on my machine it is 1.1 to 2x faster. Probably due to better cache locality.
