Now that we have the user’s attention, let’s challenge her to a quiz. We display two numbers representing a numerical sequence and then request our user to identify the next value in the sequence. For example,
The values 2,3 form two consecutive elements of a numerical sequence. What is the next value?
These values are the third and fourth elements of the Fibonacci sequence: 1, 1, 2, 3, 5, 8, 13, and so on. A Fibonacci sequence begins with the first two elements set to 1. Each subsequent element is the sum of its two preceding elements. (In Chapter 2 we write a function to calculate the elements.)
If the user enters 5, we congratulate her and ask whether she would like to try another numerical sequence. ...