Understanding Fibonacci: Recursive Method vs Binet’s Formula in Go

Kacper Bąk
2 min readMay 5, 2023


The Fibonacci sequence is a series of numbers where a number is the sum of the two preceding ones, usually starting with 0 and 1. There are numerous ways to calculate Fibonacci numbers, but two of the most popular methods are the recursive approach and Binet’s formula. In this article, we will illustrate the differences between these two methods using the Go programming language.

Recursive Method

The recursive method is the most straightforward approach to calculating Fibonacci numbers. It directly implements the mathematical definition of the Fibonacci sequence. Here is the implementation in Go:

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While the recursive method is quite simple, it has a major drawback: it performs a lot of repeated work. For large numbers, this can lead to a significant amount of unnecessary computation, making this method inefficient.

Binet’s Formula

An alternative to the recursive method is Binet’s formula, which allows you to calculate the nth Fibonacci number directly: