Print number Triangle format using C#

namespace Demo {
    class Program {
        static void Main(string[] args) {
            int i, j, k, n = 6, l = 3;
            for (i = 1; i <= 5; i++) {
                for (k = n; k >= 1; k--) {
                    Console.Write(" ");
                }
                n--;
                for (j = 1; j <= i; j++) {
                    Console.Write(" " + i);
                }
                Console.WriteLine("");
            }
            for (i = 4; i >= 1; i--) {
                for (k = l; k >= 1; k--) {
                    Console.Write(" ");
                }
                l++;
                for (j = 1; j <= i; j++) {
                    Console.Write(" " + i);
                }
                Console.WriteLine("");
            }
            Console.Read();
        }
    }
}