Delivered-To: luke@ndatech.com X-Sender: rugeley@pop3.demon.co.uk X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Sat, 15 Dec 2001 22:42:37 +0000 To: Luke Welsh From: mersenne-digest-invalid-reply-address@base.com (Mersenne Digest) (by way of Gordon Spence ) Subject: Mersenne Digest V1 #906 Mersenne Digest Saturday, November 17 2001 Volume 01 : Number 906 ---------------------------------------------------------------------- Date: Wed, 14 Nov 2001 23:40:39 +0100 From: Henk Stokhorst Subject: Re: Mersenne: prime George Woltman wrote: > In fact, one of the reasons I was a little suspicious of the report > this morning > was that I had not received the primenet email. It seems that the > eagle-eyed > Henk Stokhorst may have been the first to know that M#39 was uncovered. Achim Passauer, also from Europe, mailed me a couple of minutes after I had send the message to the list. We both check status pages regularly for progress and / or artifacts. Such as the change in the server not re-assigning exponents for factoring after they have expired. This morning when I got out of bed, I wanted to see if enough new results had been turned in for running a new report on the number of machines running Prime95 based on the file cleared.txt. Then I saw the new lines. I assumed there was some error involved, downloaded my email and found ... nothing. So I decided to write to the list without any comment, I was afraid some modification had been made to the reportgenerator and making wrong counts for two new categories. Well lucky we are, a new real candidate for #39. YotN, Henk. _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Thu, 15 Nov 2001 02:31:47 +0100 From: "Dieter Schmitt" Subject: Re: Mersenne: prime Hi, at November 1, I saved a copy of Assignments Report. Today I downloaded the new Assignments Report and the Cleared Exponents Report. Stored the three files into a database. Knowing the new prime exponent probably had been listed at Nov. 1 but isn't listed today ...... that's enough. Doing a query for inconsistency between the two Assignments Reports and another query for inconsistency between the first query result and the Cleared Exponents Report yields only a few possible entries > 3.500.000 digits (<10). I didn't look for more than 10.000.000 digits ;-) Checking these few possibilities (IPS account ID) against hrf5.txt for "Who" @GIMPS and searching GIMPS HomePage (Top Producers/expanded version/"Who" leaves only one entry matching the second condition (exponents tested = 3) :-) Of course, the new prime exponent may have been assigned after Nov., 1 ...... Yours, Dieter Schmitt _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Wed, 14 Nov 2001 21:27:48 -0500 From: Nathan Russell Subject: Mersenne: Unverified discovery makes Slashdot. For better or for worse (I think for better - it should attract a few searchers) the new Mersenne report has made it to the popular technical/open-source/geek news site Slashdot. http://slashdot.org/article.pl?sid=01/11/14/1849203&mode=nested Sadly, there are "a few" errors in this article, at first glance. I'm just posting quick comments in case any /. readers are checking this list. "There is an unconfirmed claim for Mersenne prime #39 of over 3,500,000 digits, for which a considerable amount of money has been awarded." (This prime has not received a large cash award, and any award for the finder is some time in the future, as can be seen on the prize distribution page ) - -"Mersenne primes are used to tell ET about us." (This links to an article which mentions using prime numbers to format "ascii art" types of messages, but never uses the term Mersenne prime, though a few of the smallest ones are mentioned, probably from coincidence.) - -I can't evaulate the second "message to space" link, because I don't understand the image. There's no really obvious mention of a Mersenne exponent, though, at first glance. - -"The Primenet list has confirmed that while they still need to totally test it out (which should be done by the 24th), they believe that the number found today is the 39th positive." (To my knowledge, only George has directly stated that he views the result to be correct. While I don't question his word, even if he is correct, the odds are in favor - but not *grossly* in favor - of the new prime being the 39th Mersenne - NOT the 39th prime, which is similiar to an error made in one of Cray's press releases IIRC) I couldn't care less about the grammer issues in the original article, but I must say it looks hastily typed (see ) That said, I think this could get us a LOT of new searchers. It's kind of unfortunate that it was announced prematurely, but it could seriously help us. Nathan _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Wed, 14 Nov 2001 20:43:34 -0800 From: Gerry Snyder Subject: Re: Mersenne: Mersenne prime #39 George Woltman wrote: > > Hi all, > > I've exchanged email with the discoverer. It looks like we've found > the 39th known Mersenne prime - not a hacking attempt. Well done everyone! Hooray for us! The first prime since I started. Would it be a reasonably easy task to compute and post the total (approximate) number of LL P90 years since the last prime was found? That would give a (simple-minded, inaccurate, and meaningless except to me) estimate of what percentage my almost-40 years represent toward the total effort. I know it is a small amount, dwarfed by many, but knowing the number would help me personalize the event. Congratulations and thank you to George and all the others who have made it possible for so many of us to be a part of this fun. Gerry - -- mailto:gerrysnyder@mediaone.net my work: helping generate data for: http://galileo.jpl.nasa.gov/ _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Wed, 14 Nov 2001 21:06:40 -0800 From: Luke Welsh Subject: Re: Mersenne: Unverified discovery makes Slashdot. At 09:27 PM 11/14/01 -0500, Nathan Russell wrote: >For better or for worse (I think for better - it should attract a few >searchers) the new Mersenne report has made it to the popular >technical/open-source/geek news site Slashdot. [...] >I couldn't care less about the grammer issues in the original article, Mumble, foo! about spelling and grammar. >That said, I think this could get us a LOT of new searchers. About a dozen have subscribed to this list since the /. posting. I threw a few recent digests in ndatech.com/mersenne/archives/digest V01_0876.TXT Volume 1, issue 0876 16 August 2001 through V01_0904.TXT Volume 1, issue 0904 12 November 2001 - --Luke _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Wed, 14 Nov 2001 23:38:51 -0600 (CST) From: ribwoods@execpc.com Subject: Mersenne: Fw: The Mersenne Newsletter, issue #18 Brian Beesley wrote: > On 12 Nov 2001, at 23:34, ribwoods@execpc.com wrote: [snip] > > Consequent elimination of once-L-Led Mnumbers by second-round > > factoring would account for some of the difference, though I doubt > > there've been 30,000. [snip] > 70,000 double check assignments would be expected to find about > 2,000 factors. So you agree with me that second-round factoring would account for some of the difference, but not 30,000 -- right? > > In addition, some folks have concentrated on factoring Mnumbers > > that have been L-L tested but not yet DC'd, specifically in order > > to reduce the number of necessary double-checks. > > Eh? Doesn't it make more sense to concentrate on factoring > Mnumbers that haven't yet been L-L tested? That way "success" in > finding a factor reduces the number of LL tests, as well as > (eventually) the number of double checks. Surely you don't mean to suggest that someone who receives a PrimeNet double-checking assignment that starts with some trial or P-1 factoring should stop, return that DC assignment to PrimeNet, then specifically request an assignment of factoring a Mnumber that hasn't yet been L-L tested, because that would make more sense than doing the second round of factoring on the once-L-Led Mnumber, do you? :-) Another way of looking at what those to whom I referred are doing is that we (I'm there) are performing the extra-factoring portions of potential future DC assignments. If we don't do that, whoever gets the future DC assignment will do it, so there's really no wasted effort. It's just a redistribution of work that would be done sooner or later anyway. As an old punchline goes: "If you don't, someone else will!" Ahem. Richard B. Woods _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Wed, 14 Nov 2001 22:29:09 -0800 From: Spike Jones Subject: Mersenne: paaaaaaaaarrrrrty! > George Woltman wrote: ...I'll see if I can't get Ernst > Mayer to do the official "different program - different CPU architecture" > verification.... Speaking of Ernst Mayer, lets have a Bay Area GIMPS party! Same place as before? Ill have the prime rib. {8-] spike _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Wed, 14 Nov 2001 22:38:44 -0800 From: "Aaron Blosser" Subject: RE: Mersenne: prime Hey, no fair... you're not going to share the results of your investigation? :) I guess we can all wait for verification... sigh... > -----Original Message----- > From: mersenne-invalid-reply-address@base.com [mailto:mersenne-invalid- > reply-address@base.com] On Behalf Of Dieter Schmitt > Sent: Wednesday, November 14, 2001 5:32 PM > To: mersenne@base.com > Subject: Re: Mersenne: prime > > Hi, > > at November 1, I saved a copy of Assignments Report. Today I downloaded > the > new Assignments Report and the Cleared Exponents Report. Stored the three > files into a database. > > Knowing the new prime exponent probably had been listed at Nov. 1 but > isn't > listed today ...... that's enough. > > Doing a query for inconsistency between the two Assignments Reports and > another query for inconsistency between the first query result and the > Cleared Exponents Report yields only a few possible entries > 3.500.000 > digits (<10). > > I didn't look for more than 10.000.000 digits ;-) > > Checking these few possibilities (IPS account ID) against hrf5.txt for > "Who" > @GIMPS and searching GIMPS HomePage (Top Producers/expanded version/"Who" > leaves only one entry matching the second condition (exponents tested = 3) > :-) > > Of course, the new prime exponent may have been assigned after Nov., 1 > ...... > > Yours, > > Dieter Schmitt > > > > > > > ________________________________________________________________________ _ > Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm > Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Thu, 15 Nov 2001 09:30:32 -0500 From: Jeff Woods Subject: Re: Mersenne: prime At 02:31 AM 11/15/01 +0100, you wrote: >Checking these few possibilities (IPS account ID) against hrf5.txt for "Who" >@GIMPS and searching GIMPS HomePage (Top Producers/expanded version/"Who" >leaves only one entry matching the second condition (exponents tested = 3) >:-) What was the expected completion date of that person's assigned number? (i.e. does that cross-check also hold up, raising the confidence level?) (Please don't post the number itself here if you're enterprising enough to find it. Some of us enjoy the anticipation......) _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Thu, 15 Nov 2001 16:21:06 +0100 From: "Siegmar Szlavik" Subject: Re: Mersenne: prime On Wed, 14 Nov 2001 23:40:39 +0100, Henk Stokhorst wrote: >[...] >morning when I got out of bed, I wanted to see if enough new results had >been turned in for running a new report on the number of machines >running Prime95 based on the file cleared.txt. Then I saw the new lines. talking about the cleared.txt file: I noticed some strange doublecheck entries with just "0x" in the residue column. How can that happen? Siegmar _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Thu, 15 Nov 2001 20:17:30 +0100 From: "Dieter Schmitt" Subject: Re: Mersenne: prime Hi Jeff, > What was the expected completion date of that person's assigned > number? (i.e. does that cross-check also hold up, raising the confidence > level?) Yes, it does. Completed almost two days earlier than expected, I think that's ok too. > (Please don't post the number itself here if you're enterprising enough to > find it. Some of us enjoy the anticipation......) Me too. Doublechecking on my P3-1GHz will show if I'm right :) Dieter _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Thu, 15 Nov 2001 20:29:25 -0000 From: bjb@bbhvig.uklinux.net Subject: Re: Mersenne: Unverified discovery makes Slashdot. On 14 Nov 2001, at 21:27, Nathan Russell wrote: > For better or for worse (I think for better - it should attract a few > searchers) the new Mersenne report has made it to the popular > technical/open-source/geek news site Slashdot. Indeed. Downloads of Mersenne-related software from my anon ftp server are currently running at least 10x higher than normal. (So are attempts to misuse the server - it has been explicitly configured to reject "port bouncing" to a third party address - I'm not operating an anonymising service!) > [ ... snip ...] > -"The Primenet list has confirmed that while they still need to > totally test it out (which should be done by the 24th), they believe > that the number found today is the 39th positive." (To my knowledge, > only George has directly stated that he views the result to be > correct. While I don't question his word, even if he is correct, the > odds are in favor - but not *grossly* in favor - of the new prime > being the 39th Mersenne - NOT the 39th prime, which is similiar to an > error made in one of Cray's press releases IIRC) The chance of a false zero residual after precisely (n-2) iterations due to hardware glitches or "random" software errors are surely only 1 in (2^n-1). If a zero residual is _genuinely computed_ then surely the chances are very, very, very high that a Mersenne prime has been discovered. Conversely, and assuming that the probability of any single LL test being affected by a hardware glitch or data-value-independent software error is 0.01 (which is probably a low estimate), the probablity of two runs both going wrong independently and yet returning the same _64 bit_ residual is 1 in 10000 * 2^64. This is the approximate probability that a Mersenne prime will be missed _despite_ the double-checking procedure; it is of course very small, but is absolutely COLOSSAL compared with the probability of a false discovery _without_ verification. Verification is still, of course, neccessary in order to eliminate the possibility of a systematic error (in program or hardware); also, and probably most importantly, to eliminate absolutely the chance of a "forged" discovery. BTW there are a large number of small exponents (almost all under 1 million) for which there aren't even two matching 64 bit residuals - early programs often reported residuals to 16 bits, in some cases even less. For this reason I'm selectively triple checking these cases, using old systems which are too slow and/or too memory limited to be useful for anything else. I most certainly do _not_ expect to find any missed primes! If anyone wishes to assist in the task of cleaning up this anomaly in the database, please contact me privately. As to the chance of the newly discovered unverified number being _numerically_ the 39th Mersenne prime (as opposed to the order of discovery), surely the announcement that it is "probably" M39 has to wait until all smaller exponents have been LL tested once, and not confirmed until double-checking passes that exponent. Regards Brian Beesley _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Thu, 15 Nov 2001 13:42:39 +0100 From: "jowy" Subject: Mersenne: hi everyone Hi I subscribed yesterday to the Mersenne mailing list. I'm a french student, and I'm very interested in mathematics and arithmetic. I worked with friends on a sequence of number which we suppose to give only prime numbers. It works for the 6 first numbers of the sequence, but I grows very fast. The 7th would be a 90 digits exponent. Is there a way to test this number? With Lucas Lehmer? Gauss? Thank you. _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Thu, 15 Nov 2001 17:05:46 -0500 From: George Woltman Subject: Mersenne: Re: Mersenne prime #39 At 08:43 PM 11/14/2001 -0800, you wrote: >Would it be a reasonably easy task to compute and post the total >(approximate) number of LL P90 years since the last prime was found? I don't want to be too accurate or some other clever person might figure out the exponent :) If you were to LL test every exponent with no known factor from M#38 to M#39 it would take more than 16,000 P-90 CPU years. Now we haven't done every one of those LL tests, but that total does not include all the double-checking work we've done, LL tests we've done below M#38 and LL tests we've done above M#39. I'd guess the actual total could be as high as 20,000 CPU years since M#38 was found. _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Thu, 15 Nov 2001 18:11:13 -0500 From: Nathan Russell Subject: Mersenne: Some guesses about the new prime... Known: George announced on November 14 (shortly after noon) that has verification run on M#39 will complete November 24. Trivial: It will thus take ten days, within six percent either way. Remembered, if possibly incorrectly: He owned, when he was developing the v21 client last winter, a P4-1.4 ghz. Assumed: Since then, he has not purchased another P4, overclocked the current one, or located a trusted friend owning a faster P4. Known: On a P4-1.4, an exponent in the 768 K FFT requires .060 seconds per iteration, and thus can be computed at 1,440,000 iterations per day. Known: to take 9.5 through 10.5 days would require an exponent between 13.68M and 15.12M iterations, where M is a decimal million. Known: Results are only just beginning to be returned to primenet at the extreme bottom of that range. Conjectured: George is not using his P4 for the verification - -OR- it is slower than I remembered - -OR- the new prime was found by QA - -OR- for some bizarre reason, he is not operating the machine 24/7 - merely using it as his primary machine, even for heavy gaming an hour or two per day, wouldn't goof up my assumptions all that badly. - -OR- my assumptions are otherwise fundamentally wrong. I suspect that one of the first two statements above will prove to be correct, since the humbers I concluded might contain the new prime are all over 4 million digits, and thus one would expect George to announce that the prime was "over 4 million" rather than "over 3.5 million" digits. Nathan _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Sat, 17 Nov 2001 21:53:48 +0100 From: Henk Stokhorst Subject: Mersenne: # Pentium IV L.S., Another 'eagle eyed' observation ;-) Intel Pentium 4 : 560 AMD Athlon : 8510 Intel Pentium III : 9737 Intel Pentium II : 3434 Intel Celeron : 2023 Intel Pentium Pro : 1617 Intel Pentium : 2800 AMD K6 : 1240 Intel 486 : 107 Cyrix : 1158 Unspecified type : 428 ---------------------- ------- TOTAL : 31614 YotN, Henk _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ End of Mersenne Digest V1 #906 ******************************