public static IEnumerable <int> GetAllPrimes(int greaterThan, int range, List <int> primes) => GetAllPrimes(FunctionalExtensions.PrimeCandidates(greaterThan, range), primes);
public static IEnumerable <int> GetAllPrimes() => FunctionalExtensions.PrimeCandidates().Where(HasNoDivisors);