The Fibonacci Sequence is a series of numbers that either start from 1, followed by 1, preceding with the rule that each number of the sequence is equal to sum of the preceding two numbers. For Example:

1, 1, 2, 3, 5, 8, 13, 21, 34 …

The Fibonacci sequence is coined from Leonardo Pisano (also known as Fibonacci). Fibonacci was an Italian mathematician who lived from 1170 – 1250. He used the arithmetic series to demonstrate a problem based on a pair of breeding rabbits:

“How many pairs of rabbits will be produced in a year, beginning with a single pair, if in every month each pair bears a new pair which becomes productive from the second month on?” The result can be expressed numerically as: 1, 1, 2, 3, 5, 8, 13, 21, 34 …

The Fibonacci numbers are of importance to biologists and physicists because they are frequently observed in various natural objects and phenomena. The branching patterns in trees and leaves, for example, and the distribution of seeds in a raspberry are based on Fibonacci numbers.

A Sanskrit grammarian, Pingala, is credited with the first mention of the sequence of numbers, sometime between the fifth century B.C. and the second or third century A.D. Since Fibonacci introduced the series to Western civilisation, it has had a high profile from time to time. In The Da Vinci Code, for example, the Fibonacci sequence is part of an important clue. Another application, the Fibonacci poem, is a verse in which the progression of syllable numbers per line follows Fibonacci’s pattern.

The Fibonacci sequence is related to the golden ratio, a proportion (roughly 1:1.6) that occurs frequently throughout the natural world and is applied across many areas of human endeavour. Both the Fibonacci sequence and the golden ratio are used to guide design for architecture, websites and user interfaces, among other things.