The Fibonacci Sequence, in mathematics, is a series of numbers in which each member is the sum of the two preceding numbers. For example, a series beginning 1, 2 … continues as 3, 5, 8, 13, 21, and so on. Leonardo Fibonacci (circa 1170 – circa 1240 – who was also referred to as Leonardo di Pisa) first discovered the series.

Fibonacci numbers have many interesting properties – and are widely used in mathematics. Natural patterns, such as the shape of certain sea-shells and the spiral growth of some leaves, often exhibit Fibonacci properties.