mathematics
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External Websites
- Temple University - Department of Mathematics - The fibonacci sequence, spirals and the golden mean
- Story of Mathematics - Leonardo Fibonacci
- National Center for Biotechnology Information - PubMed Central - Fibonacci numbers: A population dynamics perspective
- Art in Context - Fibonacci Sequence in Art – Using the Fibonacci Theory in Art
- Whitman College - The Fibonacci Numbers
- LiveScience - What is the Fibonacci Sequence?
Britannica Websites
Articles from Britannica Encyclopedias for elementary and high school students.
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While every effort has been made to follow citation style rules, there may be some discrepancies.Please refer to the appropriate style manual or other sources if you have any questions.
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Our editors will review what you’ve submitted and determine whether to revise the article.
External Websites
- Temple University - Department of Mathematics - The fibonacci sequence, spirals and the golden mean
- Story of Mathematics - Leonardo Fibonacci
- National Center for Biotechnology Information - PubMed Central - Fibonacci numbers: A population dynamics perspective
- Art in Context - Fibonacci Sequence in Art – Using the Fibonacci Theory in Art
- Whitman College - The Fibonacci Numbers
- LiveScience - What is the Fibonacci Sequence?
Britannica Websites
Articles from Britannica Encyclopedias for elementary and high school students.
Also known as: Fibonacci sequence
Written and fact-checked by
The Editors of Encyclopaedia Britannica
Last Updated: •Article History
- Key People:
- Fibonacci
- On the Web:
- Temple University - Department of Mathematics - The fibonacci sequence, spirals and the golden mean (May 27, 2024)
Fibonacci sequence, the sequence of numbers 1, 1, 2, 3, 5, 8, 13, 21, …, each of which, after the second, is the sum of the two previous numbers; that is, the nth Fibonacci number Fn = Fn − 1 + Fn − 2. The sequence was noted by the medieval Italian mathematician Fibonacci (Leonardo Pisano) in his Liber abaci (1202; “Book of the Abacus”), which also popularized Hindu-Arabic numerals and the decimal number system in Europe. Fibonacci introduced the sequence in the context of the problem of how many pairs of rabbits there would be in an enclosed area if every month a pair produced a new pair and rabbit pairs could produce another pair beginning in their second month. The numbers of the sequence occur throughout nature, such as in the spirals of sunflower heads and snail shells. The ratios between successive terms of the sequence tend to the golden ratio φ = (1 + Square root of√5)/2 or 1.6180…. For information on the interesting properties and uses of the Fibonacci numbers, see number games: Fibonacci numbers.
The Editors of Encyclopaedia BritannicaThis article was most recently revised and updated by Erik Gregersen.