Sieve with Lambda ex

class Primes
    {
        static double getM(Int64 varNInGetM){
            Double m = Math.Sqrt(Double.Parse(varNInGetM.ToString()));
            m = Math.Round(m, 0, MidpointRounding.AwayFromZero);
            m++;
            return m;
        }
        static List<Int64> Get_Numbers(Int64 varNInGetNum){
            List<Int64> numbers = new List<Int64>();
            numbers.Add(2);
            Console.Clear();
            for (Int64 i = 3; i < varNInGetNum; i += 2){
                numbers.Add(i);
         }
            return numbers;
        }
        static Int64[] get_amount(Int64 varNInGetAmt){
            Int64[] amount = new Int64[varNInGetAmt];
            for (Int64 i = 0; i < varNInGetAmt; i++){
                amount[i] = 0;
            }
            return amount;
        }
        static void cnslFunc(){
            Console.Clear();
            Console.SetCursorPosition(0, 0);
        }
        public List<Int64> CalcPrimes(Int64 n){
            List<Int64> numbers = Get_Numbers(n); Double m = getM(n);
            for (Int64 i = 3; i <= m; i+=2){
                if (numbers.Contains(i)){
                    numbers.RemoveAll(x => x % i == 0 && x != i);
                }
            }
            return numbers;
        }
    }