# Fibonacci numbers

### From Kook Science

**Fibonacci numbers** (*F _{n}*), named for Leonardo (figlio di Bonacci, hence

*Fibonacci*) of Pisa, are a set of numbers defined recursively, each sequential number being the sum of the previous two, as in: 0, 1, 1, 2, 3, 5, 8, 13 ...

- The greatest common divisor of any two Fibonacci numbers is also a Fibonacci number.
- Any three consecutive Fibonacci numbers, taken two at a time, are relatively prime: gcd(Fn, Fn+1) = gcd(Fn, Fn+2) = 1

## Reading

- (in Latin)
*Il Liber Abbaci di Leonardo Pisano*, Roma: Pubblicati da Baldassarre Boncompagni, 1857, http://lhldigital.lindahall.org/cdm/compoundobject/collection/math/id/8734/rec/49

## Resources

- Popova, Maria (2011-07-21),
*The Man of Numbers: How Fibonacci Changed the World*, brainpickings.org, http://www.brainpickings.org/index.php/2011/07/21/the-man-of-numbers-keith-devlin-fibonacci/