Playing with the Numbers


One of the more interesting things about the Fibonacci sequence is the interplay between the numbers; how they interrelate and their "behaviors." Some of the interactions are simple fun tricks, such as those in the children's book where I originally discovered the sequence to more complex paradoxes.

A few examples:

Divisible by 11

The sum of any ten consecutive Fibonacci numbers is always evenly divisible by 11.

1589
18144
213233
321377
534610
855987
13891,597
211442,584
342334,1841
+55+377+6,765
_________________
143 / 11=13979 / 11=8917,567 / 11=1,579


More divisibility

Here's another trick. As the consecutive integers (Fn) increase, note how they are divisible by consecutive Fibonacci numbers:

Every 3rd Fibonacci number is divisible by 2.
Every 4th Fibonacci number is divisible by 3.
Every 5th Fibonacci number is divisible by 5.
Every 6th Fibonacci number is divisible by 8.
Every 7th Fibonacci number is divisible by 13.
Every 8th Fibonacci number is divisible by 21.


Factors of Fibonacci

Another interesting characteristic of the Fibonacci sequence is that no two consecutive Fibonacci numbers have any common factors. Like this:

Fibonacci number and Prime Factors
Fibonacci NumberPrime FactorsFibonacci NumberPrime Factors
11555x11
118989
22144*2x2x2x2x3x3*
33233233
5537713x29
82x2x26102x5x61
13139873x7x47
213x715971579
342x1725842x2x2x17x19

* The 12th Fibonacci number (144) is the square of 12.
It is also the only square number in the entire sequence
well, as long as you don't count the number 1.


Here is a great site with some interesting Fibonacci Puzzles

The History Page

Natural Fibonacci (Previous Page)

Fibonacci Goes Gold (Next)

Aestetically Pleasing Fibonacci?

The Formulas for the Fibonacci Sequence.

Bibliography and some great Fibonacci links.