Tribonacci Triangle

using System;
using System.Collections.Generic;
using System.Numerics;

namespace TribonacciTriangle
{
    class TribonacciTriangle
    {
        static void Main()
        {
            List<BigInteger> tribonacciNums = new List<BigInteger>();
            for (int i = 0; i < 3; i++)
            {
                tribonacciNums.Add(BigInteger.Parse(Console.ReadLine()));
            }
            int lines = int.Parse(Console.ReadLine());
            Console.WriteLine(tribonacciNums[0]);
            Console.WriteLine("{0} {1}",tribonacciNums[1],tribonacciNums[2]);
            if (lines==2)
            {
                return;
            }
            else
            {
                BigInteger currentTrib;
                BigInteger firstTrib = tribonacciNums[0];
                BigInteger secondTrib = tribonacciNums[1];
                BigInteger thirdTrib = tribonacciNums[2];
                for (int i = 0; i < 220; i++)
                {
                    currentTrib = firstTrib + secondTrib + thirdTrib;
                    tribonacciNums.Add(currentTrib);
                    firstTrib = secondTrib;
                    secondTrib = thirdTrib;
                    thirdTrib = currentTrib;
                }
                int currentTribIndex = 3;
                int currentLineLength = 3;
                for (int i = 0; i < lines-2; i++)
                {
                    for (int k = 0; k < currentLineLength; k++)
                    {
                        Console.Write("{0} ",tribonacciNums[currentTribIndex]);
                        currentTribIndex++;
                    }
                    Console.WriteLine();
                    currentLineLength++;
                }
            }
        }
    }
}