Fibonacci numbers

Fibonacci numbers (Fn), 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)