C# Random numbers with squares in a 2d display

Can someone tell me why my second column is not the square of the fist? Here is what I have:

        const int NUM_ROWS = 10;
        const int NUM_COLS = 2;

            int[,] randint = new int [NUM_ROWS,NUM_COLS];
            Random randNum = new Random();

            for (int row = 0; row < randint.GetLength(0); row++)
            {
                randint[row,0] = randNum.Next(1,100);
                randint[row,1] = randint[row,0]*randint[row,0];

            Console.Write(string.Format("{0,5:d} {0,5:d}\n", randint[row,0], randint[row,1]));