The Fibonacci Sequence
 The Fibonacci numbers can be recursively defined as a sequence of natural numbers \(f_{1,\ }\)\(f_{2,}\)\(f_{3,...,}\)\(f_{n,...}\) such that
The recursion formula means that for every natural number \(n\) when \(n\ \ge3,\ \) the \(n^{th}\) Fibonacci number is calculated by adding the two previous terms together.  We can use this idea to generate the first few Fibonacci numbers. Looking at the figure below,  we can generate the Fibonacci Sequence.