Other commenters made other comments, but I also want to note that this article is terrible for another reason. For the first problem, they computed mathematically all the way up to calculating the recursive expression they got. After that they moved to computing the value with Python. The reason this is bad is because writing the Python code to calculate ~8.3564 was easy in the first place. They made basic mathematical analysis that wasn't even necessary, then moved to code to actually solve the problem. To be instructional, they could compute 8.333 solution mathematically (as e.g. dgacmu or vecter in this thread did) and then later move to Python for an alternative solution. This is not only confusing but also incomplete for both approaches.
