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Old 2009-05-17, 15:29   #12
10metreh
 
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Quote:
Originally Posted by Andi47 View Post
The status of "reserved", "available" and "terminated" is color-coded: yellow for reserved and light blue for available.

The Lehmer Five are saying "last editor: P. Zimmermann", but they are color-coded in light blue (meaning "available"). I checked with firefox and IE.
Ah, I see now.
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Old 2009-05-17, 19:53   #13
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i updated the Lehmer 5 reserved by P.Zimmermann (and 4788 and 130396).
the data i got was out of date and i was not sure if he works on it further.

need some time to make all things work/look fine because i'm not so familiar with drivers/guides or the current reservations (only out of this forum so far).

please post here, if there're any other errors.

attached a view of that page it should look like this. if not there's something not correct with the browser settings.
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Last fiddled with by kar_bon on 2009-05-17 at 19:57
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Old 2009-05-18, 03:01   #14
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Quote:
Originally Posted by kar_bon View Post
i updated the Lehmer 5 reserved by P.Zimmermann (and 4788 and 130396).
the data i got was out of date and i was not sure if he works on it further.
I think they're currently low priority. If there were the interest, the forum could adopt them, too.
Quote:
need some time to make all things work/look fine because i'm not so familiar with drivers/guides or the current reservations (only out of this forum so far).
Did you check the wiki article? It covers the main points about the drivers; just ask here if you have any questions.....

As far as reservations, to the best of my knowledge, we're alone in the field in the 100-200k range. Check this thread for the status of other ranges.....
Quote:
please post here, if there're any other errors.
I didn't see anything right off hand. Nice work on the table.....
Quote:
attached a view of that page it should look like this. if not there's something not correct with the browser settings.
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Old 2009-05-18, 17:12   #15
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Errrm... 2^2*7 is not the downdriver.
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Old 2009-05-20, 04:48   #16
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Default Couple of things

4788 - 27 * 32 is a guide, not a driver.

29772 - 24 * 7 is a guide.

103296 - 22 * 3 is a guide.

112638 - 22 * 32 is a guide

115302 - 26 * 3 is actually controlled by 26 * 127

139314 - 25 * 7 is a guide.

150096 - 24 * 3 is a guide.

162126 - 22 * 32 * 5 is a guide.
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Old 2009-05-20, 05:32   #17
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Quote:
Originally Posted by schickel View Post
4788 - 27 * 32 is a guide, not a driver.
<snip>
Hmmm... Either my definition of guide is messed up or most of these are incorrect. What's the definition of driver/guide you're using?

Code:
  4788  2^7*3^2*17 Guide
  9708  2^2*7  Driver
 10212  2*3    Driver
 29772  2^4    Guide
 88662  2^2    Guide
100320  2^2*7  Guide
100436  2^4*31 Guide
103296  2^2    Guide
112638  2^2    Guide
115302  2^6*127 Driver
123960  2^2    Guide
128370  2^2    Guide
129336  2^2    Guide
132792  2^4*31 Driver
132920  2^4*31 Driver
139314  2^5*7  Guide
145008  2*3    Driver
149808  2^2*7  Driver
150096  2^4    Guide
162126  2^2    Guide
167148  2^4    Guide
168912  2^4    Guide
171018  2^2    Guide
175410  2*3^2  Driver
182224  2^4*31 Driver
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Old 2009-05-20, 05:52   #18
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Quote:
Originally Posted by axn View Post
Hmmm... Either my definition of guide is messed up or most of these are incorrect. What's the definition of driver/guide you're using?
Drivers are defined in this article:
Quote:
R. K. GUY and J. L. SELFRIDGE, "What drives an aliquot sequence," Math. of Comp. v. 29, n. 129, 1975, pp. 101-107.
I'm not sure if my use of guide is correct, but I use "guide" for anything that persists, but that's not a driver.

The drivers outlined in the above article are:
Code:
2 (the downdriver)

2^2 * 7

2^3 * 3

2^3 * 3 * 5

2^4 * 31

2^5 * 3 * 7

2^6 * 127

2^9 * 3 * 11 * 31

Last fiddled with by schickel on 2009-05-20 at 05:56
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Old 2009-05-20, 06:25   #19
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Quote:
Originally Posted by schickel View Post
but I use "guide" for anything that persists, but that's not a driver.
What is the word Guy and Selfridge suggest using for things like 2^2*3, which would be classified as having the "guide" 2^2 (seems completely mad)?

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Old 2009-05-20, 06:47   #20
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Quote:
Originally Posted by 10metreh View Post
What is the word Guy and Selfridge suggest using for things like 2^2*3, which would be classified as having the "guide" 2^2 (seems completely mad)?
Here's the definition from the article:
Quote:
Originally Posted by Guy&Selfridge
Define a guide to be 2^a, together with a subset of the prime factors of \ \sigma(2^a). A driver is defined as a number \ 2^av with \ a>0, v odd, v|\sigma(2^a) and 2^{a-1}|\sigma(v). The last requirement is included so that the power of the prime 2 will tend to persist at least as well as it does for the driver 2 itself, for which the condition is trivially satisfied.
Further down, they give these as guides:
Code:
2^2

2^3

2^35

2^4

2^53

2^57
So, I have been a little, um, imprecise, in calling, for example, 2^23, a guide. The guide is actually 2^2...

And I actually have been lax: the drivers include the even perfect numbers.....
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Old 2009-05-20, 06:57   #21
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Quote:
Originally Posted by schickel View Post
Drivers are defined in this article:I'm not sure if my use of guide is correct, but I use "guide" for anything that persists, but that's not a driver.
Ok. I get one definition of guide from here (PDF file).

Basically, what forms a driver or guide depends on the factorisation of Sigma(2^a).

EDIT:- Frank was here first :)

Last fiddled with by axn on 2009-05-20 at 06:58
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Old 2009-05-20, 07:07   #22
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Quote:
Originally Posted by axn View Post
Ok. I get one definition of guide from here (PDF file).

Basically, what forms a driver or guide depends on the factorisation of Sigma(2^a).

EDIT:- Frank was here first :)
Yes, in the 3630 article, they give a quick review of the definition. If you're interested in the full proof, you have to go back to the Guy & Selfridge article.

If you have access to a library with inter-library loan privileges with a school, you can request a copy of the original article. (I got mine from a co-worker who was moonlighting from their day job at the local community college....)
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