A Fibonacci spiral created by drawing a line through the squares in the Fibonacci tiling; this one uses squares of sizes 1, 1, 2, 3, 5, 8, 13, 21, and 34; see Golden spiral

The Fibonacci numbers are a sequence of numbers in mathematics named after Leonardo of Pisa, known as Fibonacci. Fibonacci wrote a book in 1202, called Liber Abaci ("Book of Calculation"), which introduced the number pattern to Western European mathematics, although mathematicians in India already knew about it.

The first number of the pattern is 0, the second number is 1, and each number after that is equal to adding the two numbers right before it together. For example 0+1=1 and 3+5=8. This sequence goes on forever.

F0	F1	F2	F3	F4	F5	F6	F7	F8	F9	F10	F11	F12	F13	F14	F15	F16	F17	F18	F19	F20
0	1	1	2	3	5	8	13	21	34	55	89	144	233	377	610	987	1597	2584	4181	6765