Pascal's triangle

using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Numerics;

namespace SoftuniExercisesWithVariables
{
    class Program
    {
        static void Main(string[] args)
        {

            Console.WriteLine("Enter the number of rows: ");
            int rows = int.Parse(Console.ReadLine());
            int cols = rows;
            for(int i = 1; i < rows; i++)
            {
                int num = 1;
                for(int l = 0; l <= i; l++)
                {
                    Console.Write("   {0:D} ", num);

                    num = num * (i - l) / (l + 1);
                }
                Console.WriteLine();
                Console.WriteLine();
            }
        }
    }
}