RE: Mersenne: Prime Wiki
All, It seems I was too hasty. I have had a number of technical difficulties to do with DNS and apache (my fault of course) and the site was not working for a significant amount of time from my announcement. I wonder if people could let me know if it is all working. The url is now http://primes.hedges.net/ . Andy -Original Message- From: Andy Hedges [mailto:[EMAIL PROTECTED]] Sent: 17 July 2001 11:29 To: '[EMAIL PROTECTED]' Subject: Mersenne: Prime Wiki All, I have set up a Wiki to discuss Primes. It can be found at http://www.hedges.net/ . For those of you who don't know what a wiki it is a freely editable website. Go and try it for yourself to see. Andy ~~ ~~ Andy Hedges Consultant Proteus the Internet Consultancy Tel: + 44 (0)20 7566 7666 Fax: + 44 (0)20 7566 7677 Direct: + 44 (0)20 7566 7541 Web: http://www.proteus.co.uk Email: [EMAIL PROTECTED] Unit A, City Pavilion, 33 Britton St, London EC1M 5UG A Division of Proteus Ventures Ltd Registered in England: 3169362 VAT: 675007732 ~~ ~~ _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: Prime Wiki
All, I have set up a Wiki to discuss Primes. It can be found at http://www.hedges.net/ . For those of you who don't know what a wiki it is a freely editable website. Go and try it for yourself to see. Andy ~~ ~~ Andy Hedges Consultant Proteus the Internet Consultancy Tel: + 44 (0)20 7566 7666 Fax: + 44 (0)20 7566 7677 Direct: + 44 (0)20 7566 7541 Web: http://www.proteus.co.uk Email: [EMAIL PROTECTED] Unit A, City Pavilion, 33 Britton St, London EC1M 5UG A Division of Proteus Ventures Ltd Registered in England: 3169362 VAT: 675007732 ~~ ~~ _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: Proth observations
Are all primes of this form probable primes of this form? Andy -Original Message- From: Hoogendoorn, Sander [mailto:[EMAIL PROTECTED]] Sent: 23 June 2001 10:02 To: '[EMAIL PROTECTED]' Subject: RE: Mersenne: Proth observations Brian J. Beesley Wrote: My strategy is: (1) run Proth at medium priority in factoring only mode to eliminate candidates with small factors; For step 1 i use Newpgen. I think this is better configurable then proth in how far or long you want to factor. Don't know which is the fastest of the two. (2) on the same system, run PRP at low priority to check the survivors from stage 1 for probable primes; (3) on a different system (normally running Prime95), run Proth at medium priority to verify the probable primes. (If you don't have a spare system it would be best to do this in a seperate directory so as to save keep changing the Proth setup!) BTW so far _every_ probable prime I've found using PRP has been accepted as a genuine prime by Proth, though this is certainly not guaranteed. Same here If you break the run down as above you will see that some values of k yield a much smaller proportion of candidates for psuedo-prime testing than others. Or, to put it another way, some values of k give a much higher percentage of k.2^p-1 with small factors than others. For some k's you have to test more the twice as many candidates in the same range of n's Sander _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: Proth observations
Anyone have any idea why for k = 659 there are very little primes? In fact for k up to 20 there are none (I haven't found any in this range yet!). Andy -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: 23 June 2001 02:17 To: Gordon Bower; [EMAIL PROTECTED] Subject: Re: Mersenne: Proth observations Gordon Bower [EMAIL PROTECTED] observes After seeing a post on this list a few weeks ago I decided to branch out and try a few ranges from Michael Hartley's page looking for k*2^n-1 primes. I must say there is a bit of a thrill in actually discovering a new prime every day I run the program instead of proving two numbers a month composite. :) I assumed that one value of k was pretty much the same as any other as far as execution time and the chance of finding primes. To my surprise this turned out not to be so: On the P3-500, for most 650k750, it takes about 5 hours for 16000n32000 and 12 hours for 32000n48000 -- but for k=701 it took less than 2 and just over 6 hours, respectively. The phenomenon is reproducible, doesn't seem to be an artifact of other programs or reboots or suchlike. Any number theorists care to explain what is special about k=701 that makes it easy to check for primality? Fix k = 701. We check that If n == 1 (mod 2) then k*2^n == 1 (mod 3) If n == 0 (mod 4) then k*2^n == 1 (mod 5) If n == 6 (mod 8) then k*2^n == 1 (mod 17) If n == 0 (mod 3) then k*2^n == 1 (mod 7) Therefore k*2^n - 1 can be prime only if n == 2 or 10 (mod 24). We can eliminate more potential values of n using If n == 8 (mod 18) then k*2^n == 1 (mod 19) If n == 18 (mod 20) then k*2^n == 1 (mod 41) If n == 6 (mod 28) then k*2^n == 1 (mod 29) Some congruences are redundant; for example If n == 6 (mod 12) then k*2^n == 1 (mod 13) eliminates nothing new. k = 701 has less such redundancy than the typical k. _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: [slightly OT] Web discussion about distributed computing
1775*2^332181+1 is prime! (10 digits) Discovered 22-Apr-2001 How was is found? _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: VB primality test program
I chucked together a LL agorithm in Java a while back in order to benchmark some JVM's. If anyone is interested I could post the source and bytecode to my website. btw :- It is many many times slower than Prime95 (as expected). Andy -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of John R Pierce Sent: 13 March 2001 6:13 am To: Monte Westlund; [EMAIL PROTECTED] Subject: Re: Mersenne: VB primality test program I'm looking for a primality test program source code written in VB, for fun and adventure. Just want to mess around a little. Searched a little with no luck. I'm afraid VB would be awfully slow at any sort of intensive numerical work like this, and not very good with precision either, so I rather doubt anyone has spent any signficant time on anything much more sophisticated than a erathonese sieve program -jrp __ ___ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: VB primality test program
The code is a terrible mess and hardly OO. If anyone makes any radical improvements to it I would love a copy. The URL is http://www.a0a.co.uk/mirrors/mersenne/LL.zip Andy -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Monte Westlund Sent: 13 March 2001 14:30 To: [EMAIL PROTECTED] Subject: Re: Mersenne: VB primality test program On Mon, 12 Mar 2001 22:12:54 -0800, you wrote: I'm afraid VB would be awfully slow at any sort of intensive numerical work like this, and not very good with precision either, so I rather doubt anyone has spent any signficant time on anything much more sophisticated than a erathonese sieve program -jrp I know VB would not be the first choice. It's more for benchmarking some machines(Prime95 is not an option on them), and to explore a bit. Monte _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
FW: Mersenne: bug in Wordpad?
Henk Stokhorst, It is not really the OS (although UNIX does have a lot of nice tools for this type of thing) it is wordpad that is not really the most capable text editor. If you are using Windows I would suggest you try TextPad which is available for 30 day evaluation from www.textpad.com. Hope this helps, Andy ~~ ~~ Andy Hedges Consultant Proteus the Internet Consultancy Tel: + 44 (0)207 689 Fax: + 44 (0)207 689 6667 Direct: + 44 (0)207 689 6669 Web: http://www.proteus.co.uk Email: [EMAIL PROTECTED] 26 Britton St, London EC1M 5UB A Division of Proteus Ventures Ltd Registered in England: 3169362 VAT: 675007732 ~~ ~~ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Henk Stokhorst Sent: 30 October 2000 10:20 To: [EMAIL PROTECTED] Subject: Mersenne: bug in Wordpad? L.S., Whenever I have a large file (about 3.000 lines) with exponents to test (extracted from the nofactor.cmp file) and replace all the 'Test=' with 'Factor=' using wordpad (part of windows accesoires) one line gets to read 'Factorst='. Can other people reproduce this result? What OS would you recommend for such operations ;-) YotN, Henk Stokhorst _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.exu.ilstu.edu/mersenne/faq-mers.txt _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.exu.ilstu.edu/mersenne/faq-mers.txt
RE: Mersenne: GIMPSers in the news
I believe the cracking project is http://www.distributed.net/ ~~ ~~ Andy Hedges Consultant Proteus the Internet Consultancy Tel: + 44 (0)207 689 Fax: + 44 (0)207 689 6667 Direct: + 44 (0)207 689 6669 Web: http://www.proteus.co.uk Email: [EMAIL PROTECTED] 26 Britton St, London EC1M 5UB A Division of Proteus Ventures Ltd Registered in England: 3169362 VAT: 675007732 ~~ ~~ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of [EMAIL PROTECTED] Sent: Thursday, October 12, 2000 5:57 PM To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Subject: Mersenne: GIMPSers in the news Check out: http://www.cnn.com/2000/TECH/computing/10/12/britain.code.reut/index.html Of course, for me to claim Paul Leyland and Torbjorn Granlund as GIMPSers is a bit like the flea saying it owns the dog, but both have had (direct or indirect) involvement with the project in the past. Does anyone know the URL of the cracking project website mentioned in the above article? (There was no link to it from the CNN page.) -Ernst _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.exu.ilstu.edu/mersenne/faq-mers.txt _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.exu.ilstu.edu/mersenne/faq-mers.txt
