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Old 2009-01-21, 01:34   #6
cheesehead
 
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"Richard B. Woods"
Aug 2002
Wisconsin USA

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Quote:
Originally Posted by MatWur-S530113 View Post
to prevent myself from finding of already known factors I need to know them (that's about my second question).
There used to be a regularly-updated file named lowm.txt that listed all known factors. I don't know if it's still maintained somewhere on mersenne.org.

Edgington's page has a link to "mersdata.zip: lowM.txt, DATABASE, DB.nf, primeM.txt, factoredM.txt, etc., zipped"

I don't know whether its files are updated regularly. If they are, you could get lowm.txt there.

Quote:
If a number like M2251 is already completely factored, then the project doesn't need anymore list all factors, one is enough. But then at least a hint about the status of completely factored is needed imho. Or you can get such trouble like I got. Of course I know that such an exponent is not longer listet at the ECM-status page for M-numbers with known factors. But I don't look always at the ECM-page. It is simply a question of time.
So, I presume you're not doing ECM on these exponents, since otherwise how would you decide what B1 to use and how many curves to run?

Quote:
Then one can be sure about the status without looking at the ECM-status page again...
Why is looking at the ECM-status page such a time-burden for you? How often are factorizations being completed in the range of low exponents you are testing?

Download and store a copy of the page every month or so, so you can refer to that copy quickly offline.

Better yet: sign up for one of those free services that will notify you whenever a particular web page changes, so you can re-download only when it changes.

Quote:
but do you look every time at this tables for all known factors if you only want to run some ECM-curves at an exponent?
Well ... you'll have to look at some table to get all known factors for that exponent, won't you?

How about downloading and storing a copy of Edgington's table (or the file I mentioned above) once a month or so, whenever you do the same for the ECM-status page? Or put it on your page-change-notification service list.

Last fiddled with by cheesehead on 2009-01-21 at 01:57
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