private static void Main() { var primeList = PrimeSieve.PrimesList(30); foreach (var prime in primeList) { Console.Write(prime + " "); } var sieveOfEratosthenes = PrimeSieve.SieveOfEratosthenes(30); var primes = sieveOfEratosthenes .Select((x, y) => new { Index = y, IsPrime = x }) .Where(x => x.IsPrime && x.Index >= 1) .Select(x => x.Index) .ToList(); primes.ForEach(Console.WriteLine); }