primesieve is a program and C/C++ library that generates primes using a highly
optimized sieve of Eratosthenes implementation. It counts the primes below 10^10
in just 0.4 seconds on an Intel Core i7-6700 CPU (4 x 3.4 GHz). primesieve can
generate primes and prime k-tuplets up to 2^64.

WWW: https://github.com/kimwalisch/primesieve