C#

using System;
using System.Collections.Generic;
using System.Text;

namespace LotteryGenerator
{
    class RandomNumberGenerator
    {
        Random randomGenerator;

        int[] randomStorage = new int[6];

        public RandomNumberGenerator()
        {

        }

        public int RandomGenerator(int randomNumber)
        {
          
            for (int a = 0; a < randomStorage.Length; a++)
            {
                for (int aa = 0; aa < 6; aa++)
                {
                    randomGenerator = new Random();
                    randomNumber = randomGenerator.Next(1, 20);
                    randomStorage[aa] = randomNumber;

                    if (randomStorage[a] == randomNumber)
                    {
                        randomNumber = randomGenerator.Next(1, 20);
                        randomStorage[a] = randomNumber;
 
                    }
                    else
                    {

                    }
                 
                }




                Console.WriteLine("{0}", randomStorage[0]);
          
            }

            return randomNumber;
        }

    }
}