Calculating Fibonacci Numbers

Classic recursive implementation of the fibonacci series

Before we dive into what dynamic programming is, let’s have a look at a classic programming problem, the Fibonacci series. You have probably already seen it, but let’s start with a quick refresher. The Fibonacci series is a series of numbers, in which each number is the sum of the preceding two numbers. The first two numbers are 0 and 1. So, it looks like:

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, …

Here is a Python function that returns the $n^{th}$ Fibonacci number.