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#243 |
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Jun 2011
Henlopen Acres, Delaware
100001012 Posts |
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#244 |
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"William"
May 2003
New Haven
2·7·132 Posts |
Not exactly. P-1 factoring works for any number, and will find a factor P of the composite N if P-1 is sufficiently smooth. "Sufficiently smooth" means that all but the largest prime factor of P-1 are less than "B1," and the largest prime factor of P-1 is less than "B2." It is especially effective on Mersenne numbers because we know, from theory, that the divisors of 2^q-1 are all of the form 2*q+1, so we know that 2q is a divisor of P-1; this makes the unfactored part of P-1 smaller, increasing the odds it is sufficiently smooth for the method to find a factor.
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#245 | |
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"Richard B. Woods"
Aug 2002
Wisconsin USA
769210 Posts |
Quote:
There's no relationship at all between the P-1 method and the fact that Mersenne numbers differ from a power of two by 1. The "-1" in "P-1" has nothing to do with the -1 in 2p-1. The "P" in "P-1" has nothing to do with the p in 2p-1. Not even approximately! That is the only part of your response with which I disagree, because it may leave the reader with the mistaken idea that Christenson's misstatement is somehow partially correct. Last fiddled with by cheesehead on 2011-07-05 at 00:18 |
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#246 |
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Dec 2010
Monticello
179510 Posts |
I'd redact my post if I was allowed...mods, you are invited....
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#247 | |
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"Lucan"
Dec 2006
England
2·3·13·83 Posts |
Quote:
"P-1 is a factoring method" is a good start to a reply to someone who had never heard of it, and the erroneous details elicited the erudite response from William. (See another thread in the Misc Math forum) This place is instructive on a lot of levels, as long as you don't Bowdlerize the posting history. David |
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#248 |
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Nov 2003
746010 Posts |
Maybe if you bothered to do some reading about this subject you
would find out. Or don't you know how to use Google? Do us all a favor. Go away until you have read (and done the exercizes) at least one book on number theory. Maybe then, you might have sufficient knowledge to actually say something meaningful about this subject. We can suggest some references. |
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#249 |
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"Forget I exist"
Jul 2009
Dumbassville
26·131 Posts |
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#250 | |
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"Lucan"
Dec 2006
England
2·3·13·83 Posts |
Quote:
being 2kp+1 as William explained. Now respond to my post in "CPU 100%". Too many arselickers/nitpickers around here. David Last fiddled with by davieddy on 2011-07-05 at 15:16 |
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#251 |
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Jun 2011
Henlopen Acres, Delaware
7×19 Posts |
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#252 | |
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Jun 2011
Henlopen Acres, Delaware
7·19 Posts |
Quote:
http://www.tucows.com/preview/205405 "It's About Prime" The curtailed nomenclature used on this site is not so ubiquitous, and the site itself is not exactly intuitive either (or will someone point me to the "Outstanding Interface Awards it has won?) |
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#253 | |
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"Forget I exist"
Jul 2009
Dumbassville
26·131 Posts |
Quote:
http://www.google.ca/search?hl=en&q=...0l0l0l0l0l0ll0 needs more results if you're going to bring it up. |
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