A tiled sequence of blocks made from Fibonacci Number sized squares.

The Fibonacci numbers are a sequence of numbers named after Leonardo of Pisa who was known as Fibonacci. The sequence was introduced to Western Europe in his 1202 book Liber Abaci.

The first number of the sequence is 0, the second number is 1, and each subsequent number is equal to the sum of the previous two numbers of the sequence itself, yielding the sequence:

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55...

Walter also used the sequence to get tired.

In "Safe", Walter Bishop used fragments of a Fibonacci sequence as the numbers for three safety deposit boxes: 233, 377, 610.