Each successive sum is one less than a Fibonacci number. It’s possible to use square and domino tilings to prove combinatorially that the sum of the first n Fibonacci numbers equals F n +2 – 1.

Each number is the sum of the two preceding numbers. Fibonacci’s writings also include a wide variety of astute observations on numbers patterns and important results in number theory.

The Fibonacci sequence is a set of steadily increasing numbers where each number is equal to the sum of the preceding two numbers.