Talk:Perfect power

Latest comment: 3 years ago by Chrisahn in topic Duplicated summation symbols?

Disambiguation edit

This entry needs disambiguation from the Galvin Institute's Perfect Power, which is all about better electrical power. —Preceding unsigned comment added by 134.134.139.70 (talk)

Wikipedia is not a dictionary attempting to list all possible meanings of a term. Wikipedia:Disambiguation#Deciding to disambiguate says: Disambiguation is required whenever, for a given word or phrase on which a reader might use the "Go button", there is more than one Wikipedia article to which that word or phrase might be expected to lead. There doesn't appear to be information about Galvin Institute's Perfect Power in Wikipedia, so no disambiguation is needed. PrimeHunter (talk) 21:52, 20 November 2009 (UTC)Reply

Computer Program for Perfect Powers edit

Has anyone figured out a computer program for determining perfect powers in chronological order (A001597), excluding 1? Where n is the instance in the set and y is the value of that instance:

n=1, y=4
n=2, y=8
n=3, y=9
n=4, y=16
n=5, y=25
n=6, y=27
n=7, y=32
n=8, y=36

What about a math equation? Jeanlovecomputers (talk) 01:19, 14 February 2010 (UTC)Reply

It's not too hard to come up with an algorithm for producing an ordered list of perfect powers:
  1. Start with a set S containing 22 = 4, and an empty list L.
  2. Find the smallest member of S - call it x. Then x is nm for some n and m.
  3. Remove x from S and append x to L.
  4. Add nm+1 to the set S.
  5. If m is even then x is a square - suppose x = k2. Add (k+1)2 to the set S also.
  6. Repeat from 2.
So the first few iterations are:
L = {}, S = {4}. Remove 4 from S and append it to L. Add 23 = 8 and 32 = 9 to S.
L = {4}, S = {8,9}. Remove 8 from S and append it to L. Add 24 = 16 to S.
L = {4,8}, S = {9,16}. Remove 9 from S and append it to L. Add 33 = 27 and 42 = 16 to S.
L = {4,8,9}, S = {16,27}. Remove 16 from S and append it to L. Add 25 = 32 and 52 = 25 to S.
L = {4,8,9,16}, S = {27,32,25}. Remove 25 from S and append it to L. Add 53 = 125 and 62 = 36 to S.
L = {4,8,9,16,25}, S = {27,32,125,36}. Remove 27 from S and append it to L. Add 34 = 81 to S.
L = {4,8,9,16,25,27}, S = {32,125,36,81}. Remove 32 from S and append it to L. Add 26 = 64 to S.
etc. Gandalf61 (talk) 10:10, 14 February 2010 (UTC)Reply
I did something of the like to create a Qbasic program. All my program asks for is a maximum y. It scans each integer base for each integer   to y. The maximum m, which is the base, is:
 
I wish I could put up a screenshot of my program. But again, is there an equation for this? Because equations can't have booleans, can they? Jeanlovecomputers (talk) 15:46, 14 February 2010 (UTC)Reply
New information: The set A001597 without the 1 is the set A072777. Jeanlovecomputers (talk) 20:41, 16 February 2010 (UTC)Reply

Set A072777 edit

Here is a mathematical representation of the set:

 

Jeanlovecomputers (talk) 20:39, 30 April 2010 (UTC)Reply

Duplicated summation symbols? edit

In "Examples and sums", I think some of the summation symbols on the left are mistakenly duplicated. — Preceding unsigned comment added by Joseki546 (talkcontribs) 02:29, 8 May 2020 (UTC)Reply

No, they're correct. For example,   can be read like this: For all numbers   (that's the first summation symbol), calculate all their powers for exponents   (that's the second summation symbol) and sum the reciprocals of the results.
Maybe it becomes clearer when we write it without summation symbols:   Chrisahn (talk) 09:24, 8 May 2020 (UTC)Reply