Zeckendorf's theorem

The Zeckendorf's theorem states that every positive integer can be represented uniquely as a sum of one or more distinct non-neighboring or non-consecutive Fibonacci numbers. The sequence of Fibonacci numbers which add up to N is called the Zeckendorf representation of N.

Fibonacci numbers form a Fibonacci sequence where each number is the sum of the two preceding numbers. The first two terms of the sequence are 0 and 1.
First 20 Fibonacci numbers are: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 14...