This is a top-down depiction of the first nine terms of the Fibonacci Sequence: 1, 1, 2, 3, 5, 8, 13, 21, and 34. Since each term is simply the sum of the previous two terms, the next term (and the first one to not be shown here) is 55. The sequence, of course, continues forever . . . but if too much of the sequence is shown in this manner, the top of the tower would become too small to be seen.