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Old 2011-08-15, 11:57   #1
biwema
 
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Default Beginning driver/downdriver questions

Quote:
Originally Posted by Andi47 View Post
There is a need to worry - it killed the downdriver.
[Having a closer look into the factordb]

Oh. I see. My fault.
I always thought only a 2 * p could be dangerous. Now learned something.

At least there is still hope to get back the downdriver from 2^2 * p.

Last fiddled with by schickel on 2011-08-22 at 20:43 Reason: Stupid fingers made typo in title...
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Old 2011-08-15, 19:40   #2
henryzz
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Is it always possible to gain the downdriver within 3 iterations from any driver? Maybe 4 iterations?
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Old 2011-08-22, 05:49   #3
JohnFullspeed
 
May 2011
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Default What???

Quote:
Originally Posted by henryzz View Post
Is it always possible to gain the downdriver within 3 iterations from any driver? Maybe 4 iterations?
I dont know what you call a ''DRIVER" and a downdriver
Is someone can explain...

Merci
John
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Old 2011-08-22, 06:08   #4
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a driver is something you find from one iteration to another, like 2^2*7, 2*3 and make the sequence grow.
In some case, when the decomposition of the composite is 2* large integer, the sigma of the number is smaller than him., driving the sequence lower and lower, so it is a downdriver.
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Old 2011-08-22, 06:12   #5
schickel
 
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Quote:
Originally Posted by JohnFullspeed View Post
I dont know what you call a ''DRIVER" and a downdriver
Is someone can explain...

Merci
John
Drivers are defined in an article in Mathematics of Computation in 1975 by Richard K Guy and John Selfridge. You can find the article free of charge here. There is a later article clarifying the proof. That one is available here.

(Thanks to the American Mathematical Society who has made its older articles available free of change.)
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Old 2011-08-22, 11:01   #6
JohnFullspeed
 
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Default Thanks for the link

Perhaps you have a option but where?


In a PDF file like here.you have a zoom (I read only size 26)
but when you print the doc the police is the original siize(10,12...)
Why?
PDF is well a Print Format

Like Millions of humans I am neer blind
Adobbe forget us?

John
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Old 2011-08-22, 20:41   #7
schickel
 
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Quote:
Originally Posted by JohnFullspeed View Post
Perhaps you have a option but where?


In a PDF file like here.you have a zoom (I read only size 26)
but when you print the doc the police is the original siize(10,12...)
Why?
PDF is well a Print Format

Like Millions of humans I am neer blind
Adobbe forget us?

John
Unfortunate, but true. PDF tries to recreate the represented document exactly, which means it's hard to resize something after it's initially printed.

Try the attached. I upsized the text. (I was reluctant to post the driver article because of the nature of the release I got, but since it is freely available on ams.org now, I think this is a little more allowed...)

Be aware: without some more work some of the equations don't fit the page correctly, with the text overflowing off the right margin, but the main article text should be easier to manage.
Attached Files
File Type: pdf LargeDrives.pdf (215.1 KB, 109 views)
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