2.4

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            int k = 0;
            for (int i = 0; i < 14; i++)
            {
                Console.WriteLine(k +=7);
                Console.ReadKey();
            }
        }
    }
}