Fibonacci numbers without programming
09-20-2017, 03:13 PM
Post: #1
 stored Junior Member Posts: 11 Joined: Sep 2016
Fibonacci numbers without programming
Amazingly, most of simple non-scientific calculators allow to produce sequence of Fibonacci numbers with only 2 key press per number:

AC 1 + = + = + = ...

On HP 17b I found solutions with 6 keys per number:
For init: 0 ENTER 1 ENTER
Next number: SHIFT LAST + SHIFT LAST =

How to do this on RPN calculators like HP 12C, HP 42S (without programming)?
09-20-2017, 03:51 PM
Post: #2
 Didier Lachieze Senior Member Posts: 1,023 Joined: Dec 2013
RE: Fibonacci numbers without programming
With a RPN calculator you can do:
Code:
1 ENTER 1 + LASTx x<>y + LASTx x<>y + ...
09-20-2017, 04:11 PM
Post: #3
 stored Junior Member Posts: 11 Joined: Sep 2016
RE: Fibonacci numbers without programming
It worked. Good solution.
Thanks you!
09-20-2017, 05:03 PM (This post was last modified: 09-20-2017 05:03 PM by Dieter.)
Post: #4
 Dieter Senior Member Posts: 2,184 Joined: Dec 2013
RE: Fibonacci numbers without programming
(09-20-2017 03:13 PM)stored Wrote:  How to do this on RPN calculators like HP 12C, HP 42S (without programming)?

On calculators with RCL-arithmetics and direct stack access (e.g. the 42s) you can do this:

1 ENTER +
RCL+ ST L
RCL+ ST L
RCL+ ST L
...

Depending on the model this may take the same four keys as the Lastx x<>y + method... or maybe less: on the WP31s and 34s it's simply [RCL] [+] [L].

Dieter
09-20-2017, 07:41 PM
Post: #5
 John Keith Member Posts: 247 Joined: Dec 2013
RE: Fibonacci numbers without programming
On the RPL series, if you enter two 1's on the stack, the sequence OVER OVER + will fill the stack with the Fibonacci series. Three key presses if you have the PROGRAM/STACK menu active.

John
09-20-2017, 08:34 PM
Post: #6
 Gerson W. Barbosa Senior Member Posts: 1,056 Joined: Dec 2013
RE: Fibonacci numbers without programming
(09-20-2017 07:41 PM)John Keith Wrote:  On the RPL series, if you enter two 1's on the stack, the sequence OVER OVER + will fill the stack with the Fibonacci series. Three key presses if you have the PROGRAM/STACK menu active.

Or two, if you do DUP2 + instead.

Gerson.
09-20-2017, 08:55 PM
Post: #7
 Csaba Tizedes Member Posts: 274 Joined: May 2014
RE: Fibonacci numbers without programming
Any blind programmable CASIO:

Code:
[1][KIN][1]
Then repeat the following:
Code:
[+][x↔K1][=]

Csaba
09-20-2017, 09:54 PM
Post: #8
 Jim Horn Member Posts: 151 Joined: Dec 2013
RE: Fibonacci numbers without programming
If you have a matrix math capable calculator, fill the stack with:
[[1 1]
[1 0]]

and press "X" (multiply) repeatedly. A one button solution!
09-20-2017, 10:05 PM
Post: #9
 John Keith Member Posts: 247 Joined: Dec 2013
RE: Fibonacci numbers without programming
(09-20-2017 08:34 PM)Gerson W. Barbosa Wrote:
(09-20-2017 07:41 PM)John Keith Wrote:  On the RPL series, if you enter two 1's on the stack, the sequence OVER OVER + will fill the stack with the Fibonacci series. Three key presses if you have the PROGRAM/STACK menu active.

Or two, if you do DUP2 + instead.

Gerson.

DOH! That's what I get for posting first, thinking later. :-)
09-20-2017, 10:38 PM
Post: #10
 AlexFekken Member Posts: 151 Joined: May 2016
RE: Fibonacci numbers without programming
(09-20-2017 09:54 PM)Jim Horn Wrote:  If you have a matrix math capable calculator... A one button solution!

What I really like about this solution is that it does not rely at all on the coeffificents in the recursion being 1 or on the order of the recursion being only 2. That's the difference between doing math and doing arithmetic :-)
09-20-2017, 10:40 PM (This post was last modified: 09-20-2017 10:46 PM by Gerson W. Barbosa.)
Post: #11
 Gerson W. Barbosa Senior Member Posts: 1,056 Joined: Dec 2013
RE: Fibonacci numbers without programming
(09-20-2017 10:05 PM)John Keith Wrote:
(09-20-2017 08:34 PM)Gerson W. Barbosa Wrote:  Or two, if you do DUP2 + instead.

Gerson.

DOH! That's what I get for posting first, thinking later. :-)

I have many “OVER OVER” sequences permanently written in the files, like this one here (third code box in post #20). Yet DUP2 was available in my first RPL calculator, a 28S. Hopefully I’ll never forget :-)
09-20-2017, 11:18 PM
Post: #12
 AlexFekken Member Posts: 151 Joined: May 2016
RE: Fibonacci numbers without programming
(09-20-2017 09:54 PM)Jim Horn Wrote:  If you have a matrix math capable calculator, .... A one button solution!
I really like this one: so general. The difference between doing math and arithmetic :-)
02-17-2018, 03:17 PM
Post: #13
 Gamo Senior Member Posts: 333 Joined: Dec 2016
RE: Fibonacci numbers without programming
On any HP RPN Calculator can do Fibonacci Sequence manually without the use of program.

Key this in and repeat second line below.

1 ENTER 1 ENTER RollDown RollDown +
ENTER ENTER RollDown RollDown +
.
.
.
.

Gamo
02-17-2018, 04:49 PM
Post: #14
 ttw Member Posts: 133 Joined: Jun 2014
RE: Fibonacci numbers without programming
However, with a short program, one can get any Fibonacci number by entering the index. (Except for overflow).

<< 5 Sqrt 1 + 2 / SWAP ^ 5 Sqrt / 0 RND>>
02-19-2018, 06:29 PM
Post: #15
 xerxes Member Posts: 64 Joined: Jun 2014
RE: Fibonacci numbers without programming
(09-20-2017 08:55 PM)Csaba Tizedes Wrote:  Any blind programmable CASIO:

Code:
[1][KIN][1]
Then repeat the following:
Code:
[+][x↔K1][=]

Csaba

A shorter solution for the FX-180P line:
Code:
1 + +
Repeat:
Code:
x↔y =

Calculator Benchmark
 « Next Oldest | Next Newest »

User(s) browsing this thread: 1 Guest(s)