## Leonardo Fibonacci discovered the sequence which converges on phi.

In the 12th century, Leonardo Fibonacci wrote in Liber Abaci of a simple numerical sequence that is the foundation for an incredible mathematical relationship behind phi. This sequence was known as early as the 6th century AD by Indian mathematicians, but it was Fibonacci who introduced it to the west after his travels throughout the Mediterranean world and North Africa.

Starting with 0 and 1, each new number in the sequence is simply the sum of the two before it.

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, . . .

The ratio of each successive pair of numbers in the sequence approximates phi (1.618. . .) , as 5 divided by 3 is 1.666…, and 8 divided by 5 is 1.60.

The table below shows how the ratios of the successive numbers in the Fibonacci sequence quickly converge on Phi. After the 40th number in the sequence, the ratio is accurate to 15 decimal places.

### 1.618033988749895 . . .

## Compute any number in the Fibonacci Sequence easily!

Here are two ways you can use phi to compute the nth number in the Fibonacci sequence (f_{n}).

If you consider 0 in the Fibonacci sequence to correspond to n = 0, use this formula:

f_{n} = Phi^{ n} / 5^{½}

Perhaps a better way is to consider 0 in the Fibonacci sequence to correspond to the 1st Fibonacci number where n = 1 for 0. Then you can use this formula, discovered and contributed by Jordan Malachi Dant in April 2005:

f_{n} = Phi^{ n} / (Phi + 2)

Both approaches represent limits which always round to the correct Fibonacci number and approach the actual Fibonacci number as n increases.

## The ratio of successive Fibonacci numbers converges on phi

Sequence in the sequence | Resulting Fibonacci number (the sum of the two numbers before it) | Ratio of each number to the one before it (this estimates phi) | Difference from Phi |

0 | 0 | ||

1 | 1 | ||

2 | 1 | 1.000000000000000 | +0.618033988749895 |

3 | 2 | 2.000000000000000 | -0.381966011250105 |

4 | 3 | 1.500000000000000 | +0.118033988749895 |

5 | 5 | 1.666666666666667 | -0.048632677916772 |

6 | 8 | 1.600000000000000 | +0.018033988749895 |

7 | 13 | 1.625000000000000 | -0.006966011250105 |

8 | 21 | 1.615384615384615 | +0.002649373365279 |

9 | 34 | 1.619047619047619 | -0.001013630297724 |

10 | 55 | 1.617647058823529 | +0.000386929926365 |

11 | 89 | 1.618181818181818 | -0.000147829431923 |

12 | 144 | 1.617977528089888 | +0.000056460660007 |

13 | 233 | 1.618055555555556 | -0.000021566805661 |

14 | 377 | 1.618025751072961 | +0.000008237676933 |

15 | 610 | 1.618037135278515 | -0.000003146528620 |

16 | 987 | 1.618032786885246 | +0.000001201864649 |

17 | 1,597 | 1.618034447821682 | -0.000000459071787 |

18 | 2,584 | 1.618033813400125 | +0.000000175349770 |

19 | 4,181 | 1.618034055727554 | -0.000000066977659 |

20 | 6,765 | 1.618033963166707 | +0.000000025583188 |

21 | 10,946 | 1.618033998521803 | -0.000000009771909 |

22 | 17,711 | 1.618033985017358 | +0.000000003732537 |

23 | 28,657 | 1.618033990175597 | -0.000000001425702 |

24 | 46,368 | 1.618033988205325 | +0.000000000544570 |

25 | 75,025 | 1.618033988957902 | -0.000000000208007 |

26 | 121,393 | 1.618033988670443 | +0.000000000079452 |

27 | 196,418 | 1.618033988780243 | -0.000000000030348 |

28 | 317,811 | 1.618033988738303 | +0.000000000011592 |

29 | 514,229 | 1.618033988754323 | -0.000000000004428 |

30 | 832,040 | 1.618033988748204 | +0.000000000001691 |

31 | 1,346,269 | 1.618033988750541 | -0.000000000000646 |

32 | 2,178,309 | 1.618033988749648 | +0.000000000000247 |

33 | 3,524,578 | 1.618033988749989 | -0.000000000000094 |

34 | 5,702,887 | 1.618033988749859 | +0.000000000000036 |

35 | 9,227,465 | 1.618033988749909 | -0.000000000000014 |

36 | 14,930,352 | 1.618033988749890 | +0.000000000000005 |

37 | 24,157,817 | 1.618033988749897 | -0.000000000000002 |

38 | 39,088,169 | 1.618033988749894 | +0.000000000000001 |

39 | 63,245,986 | 1.618033988749895 | -0.000000000000000 |

40 | 102,334,155 | 1.618033988749895 | +0.000000000000000 |

Tawfik Mohammed notes that 13, considered by some to be an unlucky number, is found at position number 7, the lucky number!

## The Fibonacci Sequence and Gambling or Lotteries

Some people hope that Fibonacci numbers will provide an edge in picking lottery numbers or bets in gambling. The truth is that the outcomes of games of chance are determined by random outcomes and have no special connection to Fibonacci numbers.

There are, however, betting systems used to manage the way bets are placed, and the Fibonacci system based on the Fibonacci sequence is a variation on the Martingale progression. In this system, often used for casino and online roulette, the pattern of bets placed follows a Fibonacci progression: i.e., each wager should be the sum of the previous two wagers until a win is made. If a number wins, the bet goes back two numbers in the sequence because their sum was equal to the previous bet.

In the Fibonacci system the bets stay lower then a Martingale Progression, which doubles up every time. The downside is that in the Fibonacci roulette system the bet does not cover all of the losses in a bad streak.

An important caution: Betting systems do not alter the fundamental odds of a game, which are always in favor of the casino or the lottery. They may just be useful in making the playing of bets more methodical, as illustrated in the example below:

Round | Scenario 1 | Scenario 2 | Scenario 3 |

Bet 1 | Bet 1 and lose | Bet 1 and lose | Bet 1 and win |

Bet 2 | Bet 1 and lose | Bet 1 and lose | Bet 1 and win |

Bet 3 | Bet 2 and win | Bet 2 and lose | Bet 1 and lose |

Bet 4 | - | Bet 3 and win | Bet 1 and lose |

Bet 5 | - | - | Bet 2 and win |

Net Result | Even at 0 | Down by 1 | Ahead by 2 |

matthew C Culver says

DANTS FORMULA IS THE LOG OF ONE DEFINED DIMENSION TO THE DIVISION OF ITSELF

Matt says

I am very curious about the “sequence” and how it affects us as people in our daily lives. John says it is the combinations of moves and or optimization one must make in order to complete a task, taking in scenarios in which one would never lose. Could you point me to more information how this connects with our lives, past, present and future? and if in laymen terms that would be much better.

matthew C Culver says

FIBONACCI is the combinations of moves and or optimization

one must make inorder to complete a task, taking in scenarios

in which one would never lose.

John says

Thank you for your input and clarification sir. The original way is golden! You can never loose! Any other way can lead to a path of darkness and confusion as you try to come full circle.

Patrick says

I love the column, but it hits something of a pet peeve. Check out

http://en.wikipedia.org/wiki/Series_(mathematics)

to see the distinction between a sequence and a series. Basically, everywhere you see the word “series”, it should be “sequence”. Instead of “Sequence in the series”, how about “Position in the sequence”.

Gary Meisner says

Thank you for the insight on this. There seem to be differing definitions depending on the source. Dictionary.com defines series as “a group or a number of related or similar things, events, etc., arranged or occurring in temporal, spatial, or other order or succession; sequence” followed by “Series, sequence, succession are terms for an orderly following of things one after another. Series is applied to a number of things of the same kind, usually related to each other, arranged or happening in order: a series of baseball games. Sequence stresses the continuity in time, thought, cause and effect, etc.: The scenes came in a definite sequence. Succession implies that one thing is followed by another or others in turn, usually though not necessarily with a relation or connection between them: succession to a throne; a succession of calamities.” Google lists 1.2 million references for “Fibonacci Series” and 2.1 million references for “Fibonacci sequence” so both are in common usage, although sequence is apparentely more prevalent. I’ll review your suggested changes and include these comments to the post for clarification.

Lou Hawthorne says

Gary – Very interesting article and table. FYI, Patrick is correct that series and sequence have specific meanings and are not interchangeable to mathematicians, no matter what Google or various dictionaries say. To mathematicians, a sequence is a progression of numbers generated by a function, whereas a series is the sum of numbers in a sequence. Your article is too good in other respects to use these terms in non-mathematical ways.

Best,

Lou

Gary Meisner says

Thanks, Lou. I’ve taken your advice and changed the references in the article to sequence from series.

nick fortis says

And a product as well.

Shelley says

I am very curious about the “sequence” and how it affects us as people in our daily lives. John says it is the combinations of moves and or optimization one must make in order to complete a task, taking in scenarios in which one would never lose. Could you point me to more information how this connects with our lives, past, present and future? and if in laymen terms that would be even better.

Thanks for your kind consideration of my request.

Cheers Shelley

ben says

is the difference from phi column actually an inverted fibonacci series where you skip one number each time? 1+2=3, 2+3=5 but only 1,2 & 5 are in the sequence. next is 14, 36…

Janne says

Thank you …

Martin says

How brilliant he must have been. And now we use calculators. Thanks — Martin

Mike E. says

Nor sure if you’ve seen the work done by artist Vi Hart posted on Kahn Academy. If not, enjoy. Love your site.

https://www.khanacademy.org/math/recreational-math/vi-hart

hardik says

awesome!!!!!!!!!!!!!!!!!!!!!!!!!!

HHHProgram says

Hey Gary Meisner,

Excellent article for the Fibonacci series of course this blog is doing a very good job of serving useful information. I’m proud to be a part of its Readers community.

For the Fibonacci programs in different languange like C language,JAVA,C# must visit http://www.hhhprogram.com/2013/05/fibonaccci-series.html

Results 2013 says

Thank you hardik for your Good job.

stephen says

Is it posible that Fibonaccis Sequence could explane the bigbang or how time started????

Eros says

Yes, the big bang was the result of the Golden Number being divided by zero. So, never do that!

Eros.

Gary Meisner says

Good humor. Division by zero is known to mess up calculators and spreadsheets, but current thinking in cosmology reflects a different cause. There is an interesting relationship though between 0 divided by 1 and Phi discussed on Theology page.

Shivaji Results says

I was looking for the real time application of Fibonacci Sequence and got it from your blog. Thank you Very Much for your awesome Article.

William Vennard says

One can begin with any two random numbers and as long as the Fibonacci pattern is followed, they will eventually come out to 1.6180339–!

Gary Meisner says

That is true. The Fibonacci numbers have some very unique properties of their own, however, and there’s something mathematically elegant to start with 0 and 1 rather than two randomly selected numbers. Either way, this illustrates the significance of the additive property of the Fibonacci series that allows us to derive phi from the ratios of the successive numbers.

AmberEliana says

However, Fibonacci sequence converges faster than other similar sequences.

Adarsh nimje says

CAN ANYONE TELL ME WHAT IS THE RATIO OF AN ANGLE OF GOLDEN TRIANGLE???????

pat says

Adarsh, a “ratio” requires two things. Your question isn’t clear because you don’t say what two things you want the “ratio” of.

pat says

I noticed that there is actually an “exact” Fibonacci sequence. If you use phi (0.618…) as the first number and one as the second number, you get the sequence:

0.6180339887, 1, 1.6180339887, 2.6180339887, 4.2360679775, 6.8541019662…

I say it is “exact” because the ratio between successive terms is always exactly Phi (1.618…), with no approximation. This sequence has some interesting properties. The terms actually begin to approach integers as they get larger.

Gary Meisner says

The sequence of exponential powers of phi does have unique properties, but technically speaking it is not the sequence discovered by Fibonacci and named after him.

Ted says

Hi Gary,

If the Fibonacci sequence is the sequence starting with 1, what do we call the infinite number of other sequences whose ratios all converge on Phi in a similar manner?

Any two starting numbers, including fractions or even negative numbers, in any combination, will work.

Regards,

Ted.

Ted says

Sorry, misspelled Fibonacci!

Ted.

12th Class Result 2014 says

That depends on who invent the series. yes, there are many such series out there, but we need to identify them and need to prove their concept in front of the world. Publishing a paper on it will do the task.

tristan says

that’s pretty easy

tina says

thanks for helping :))))))))))))))))))))))

Result 2013 says

To mathematicians, a sequence is a progression of numbers generated by a function, whereas a series is the sum of numbers in a sequence. Your article is too good in other respects to use these terms in non-mathematical ways.

Nick Fortis says

Indeed. But a sequence need NOT be “generated by a function.” E.g.,

2 6 13 8 1 41 (power ball choices, say), is a sequence. I may or may not wish to sum the sequence or form its product. Naf Saratoga CA

Nick Fortis says

OK: again . USUALLY generated. The prime numbers form a sequence; One can surely determine them using various techniques, but no one can generate them.

Unless you, perhaps, have solved RH. Or something related thereto.

Naf

N A Fortis says

Exception:

“Random Sequence. A sequence that is irregular, non repetitive, and hapahazard. … …

A completely satisfactory definition of randomn sequence is yet to be discovered. However, test of randomness can be made; e.g., by subdividing the sequence into blocks and using the chi-square test to to analyze the frequencies of occurrence of specified individual integers… … …A table of one million random digits has been published”

Ted says

I’ve also noticed that the ratio of successive pairs of numbers in other sum sequences converge as well. For example, take any three numbers and sum them to make a fourth, then continue summing the last three numbers in the sequence to make the next. The ratio of successive pairs of numbers in this sequence converges on 1.83928675521416….

Similarly, summing the last four, five, six, seven and eight numbers converge on different values which themselves appear to converge on 2.0 as you increase the quantity of numbers which are summed. ie.;-

Numbers Convergent value

Summed

2 1.61803398874989…

3 1.83928675521416…

4 1.92756197548293…

5 1.96594823664549…

6 1.98358284342433…

7 1.99196419660503…

8 1.99603117973541…

Regards,

Ted.

Ted says

I guess I should have Googled this earlier;-

http://en.wikipedia.org/wiki/Generalizations_of_Fibonacci_numbers

Regards,

Ted.

results 2014 says

Yep, that is the correct citation you’ve indicated Ted.

Mahesh chandra says

I do appreciate and you have done nice work!! and i always use http://en.wikipedia.org/wiki/Series_(mathematics), gives more information

zubaida says

can someone tell me who the author of this article is? I would love to credit him or her for this wonderful job in my math project.

Gary Meisner says

Unless otherwise noted, all articles on this site are written by Gary Meisner. See http://www.goldennumber.net/content-images-use for details on references.

N J Smith says

Mr. Hawthorne’s comment is interesting, especially with respect to dictionary definitions.

One sees that not all sequences can be generated by a function.

The random sequence is one such (pg 247, Mathematics Dictionary, James & James, 5th Ed 1992.)

“Random Sequence. A sequence that is irregular, non repetitive, and hapahazard. … …

A completely satisfactory definition of random sequence is yet to be discovered. However, test of randomness can be made; e.g., by subdividing the sequence into blocks and using the chi-square test to to analyze the frequencies of occurrence of specified individual integers… … …A table of one million random digits has been published”

Njs

N J Smith says

Mr. Hawthorne’s comment is interesting, especially with respect to dictionary definitions.

One sees that not all sequences can be generated by a function.

The random sequence is one such (pg 247, Mathematics Dictionary, James & James, 5th Ed 1992.

“Random Sequence. A sequence that is irregular, non repetitive, and hapahazard. … …

A completely satisfactory definition of randomn sequence is yet to be discovered. However, test of randomness can be made; e.g., by subdividing the sequence into blocks and using the chi-square test to to analyze the frequencies of occurrence of specified individual integers… … …A table of one million random digits has been published”

Njs

harsh says

How brilliant he must have been. And now we use calculators. Thanks for this informative article.

Dean Huffman says

solved 432hz divided by 2 216,108,54, 27,13.5,6.75,3.375,1.6875 the atom inside a nucleus my head ,the one inside ,can see alot.

Gaurav says

Now a days we use calculators….How brilliant he must have been.

deepjyoti deb says

can u pls tell me dat which Indian or in which Indian book phi is discovered 1st

JanetAlexander says

Correct pronunciation is FEE

Gary Meisner says

Like many other words in the English language, the answer depends on who you ask and where you ask it. See http://www.goldennumber.net/pronouncing-phi/ for a more in depth discussion.

Wesley Horton says

Question:

If you pick a random number N (lets say 17) and N+1 (18) and started the sequence from those two numbers, does the series converge on phi or some other infinite series?

Gary Meisner says

You can start with any two numbers, add then together and continue in the same way and the ratio of the larger to the smaller will converge on phi.