[QUOTE=Christenson;265340]
Do you want me to feed M46789177 to mfaktc for 68 to 71 bits? It would start sometime tomorrow, GMT-4=E. Coast US time.[/QUOTE]

Well I'm already working on it, core #3 of 4. It's 17% done and will be finished before the end of this month (Jul 26 estimate).

[QUOTE=Christenson;265340]P-1 is a factoring method that depends on the fact that mersenne numbers are one different than an even power of two.[/QUOTE]

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.

[QUOTE=Christenson;265340]P-1 is a factoring method that depends on the fact that mersenne numbers are one different than an even power of two.[/QUOTE]No.

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 [I]-1[/I] in 2[sup]p[/sup]-1.

The "P" in "P-1" has nothing to do with the [I]p[/I] in 2[sup]p[/sup]-1.

[QUOTE=wblipp;265362]Not exactly.[/QUOTE]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.

I'd redact my post if I was allowed...mods, you are invited....

[QUOTE=Christenson;265455]I'd redact my post if I was allowed...mods, you are invited....[/QUOTE]

No mods, please don't!

"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

[QUOTE=LiquidNitrogen;265337]And what does P-1 refer to?[/QUOTE]

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.

[QUOTE=R.D. Silverman;265512] Or don't you know how to use Google?
[/QUOTE]

if he doesn't I'd be happy to give him a link to make advanced searches ( though I don't do them enough) . I've tried teaching my mom why [TEX].\bar {9} =1 [/TEX] so teaching someone else Google shouldn't be that hard.

You keep coming back for more, Richard...
 

[QUOTE=cheesehead;265446]No.

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 [I]-1[/I] in 2[sup]p[/sup]-1.

The "P" in "P-1" has nothing to do with the [I]p[/I] in 2[sup]p[/sup]-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.[/QUOTE]

The "-1" has got a lot to do with factors of 2[SUP]p[/SUP]-1
being 2kp+1 as William explained.

Now respond to my post in "CPU 100%".

Too many arselickers/nitpickers around here.

David

[QUOTE=R.D. Silverman;265512]Or don't you know how to use Google?
[/QUOTE]

As one of their first 100 employees, I guess not.

[QUOTE=science_man_88;265514]if he doesn't I'd be happy to give him a link to make advanced searches ( though I don't do them enough) . I've tried teaching my mom why [TEX].\bar {9} =1 [/TEX] so teaching someone else Google shouldn't be that hard.[/QUOTE]

And I did write a Factoring Program back in 1998 for the Mac:

[URL]http://www.tucows.com/preview/205405[/URL]

"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?)

[QUOTE=LiquidNitrogen;265533]And I did write a Factoring Program back in 1998 for the Mac:

[URL]http://www.tucows.com/preview/205405[/URL]

"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?)[/QUOTE]

I'm a idiot and even i can find most things. and by the way:

[url]http://www.google.ca/search?hl=en&q=%22Outstanding+Interface+Award%22+%2B+google&oq=%22Outstanding+Interface+Award%22+%2B+google&aq=f&aqi=&aql=&gs_sm=s&gs_upl=0l0l0l0l0l0l0l0l0l0l0ll0[/url] needs more results if you're going to bring it up.