20040507, 04:19  #12 
"William"
May 2003
New Haven
4444_{8} Posts 
How long does the contest run?
I used all numbers for "a" in my search. I think the impact of composite versus prime would be small. It would tend towards primes at small coefficients because composites would not exclude any new factors. At larger coefficients the composites would often weed out more than one prime, so the advantage probably switches to composite coefficients. 
20040508, 08:37  #13  
May 2004
3^{2} Posts 
Quote:


20040508, 11:25  #14 
Mar 2004
3·127 Posts 
In this case I recomend you to search primorial twins (sieve using NewPGen, and verify with pfgw) which are larger than the largest one thusfar this year.
If you have such a prime, you can try to beat the 44k bit candidate. 
20040530, 18:28  #15  
"William"
May 2003
New Haven
2^{2}·3^{2}·5·13 Posts 
Quote:
William 

20040601, 06:15  #16 
May 2004
3^{2} Posts 
it's not quite over, we've got until the 10th
I found an 11287 bit one, but someone has beaten me with a 34522 bit number, which I haven't tried to beat The number are viewable here: http://www.it.usyd.edu.au/~dasymond/cookies.html thanks a lot for your help! :) 
20040601, 10:15  #17 
Aug 2003
Upstate NY, USA
2·163 Posts 
that's a little larger than the http://www.alpertron.com.ar/ECM.HTM ecm can handle

20040601, 14:15  #18  
"William"
May 2003
New Haven
2^{2}×3^{2}×5×13 Posts 
Quote:
I started NewPgen on a range that I picked with too little preanalysis. When I got around to the analysis, the range was too large and the numbers were too large to have much hope of finishing in the time available. I let NewPgen run a couple of weeks  it removed about 84% of the range. With unlimited time it should be sieved more, but with a fixed deadline it was time to switch over to PRP testing using PFGW. In a week of PRP testing I've found about six primes, but no twin primes. I estimate that about one in a thousand primes will be part of a twin prime, so finding one in the next nine days requires incredible luck or incredible computing power. These numbers are over 19,000 digits (over 63,000 bits), so if you happen to find an oreo it will also be the eleventh largest known twin prime, and will be listable on Chris Caldwell's Top Twenty Twins Page. Let me know if you want to put some computers to work. After June 10th I may return to sieving in an effort to find a listable twin. William 

20040602, 03:57  #19 
May 2004
3^{2} Posts 
if you send me some pfgw inputs i'd be more than happy to test them for a while  i have a couple of machines here that i can run it on  if you could email phatfil@optusnet.com.au that'd be great
thanks a lot! Last fiddled with by Agrajag on 20040602 at 03:58 
20040602, 05:19  #20  
"William"
May 2003
New Haven
2^{2}×3^{2}×5×13 Posts 
Quote:
William 

20040609, 09:34  #21 
May 2004
3^{2} Posts 
time's up, guess I wasn't lucky enough :/
thanks a lot anyway! here's a list of prp's i found in that range (had 4 computers working on different parts of the range): 10000100001154*45007#1 10000100007604*45007#1 10000100011400*45007#1 10000100013880*45007#1 10000100016626*45007#1 10000100027119*45007#1 10000100029300*45007#1 10000100030374*45007#1 10000100034759*45007#1 10000100045165*45007#1 10000100050352*45007#1 10000100067637*45007#1 10000100068769*45007#1 10000100069793*45007#1 10000100071160*45007#1 10000100074401*45007#1 10000100309043*45007#1 10000100309745*45007#1 10000100310663*45007#1 10000100316772*45007#1 10000100318505*45007#1 10000100331208*45007#1 10000100621073*45007#1 10000100632859*45007#1 10000100636178*45007#1 10000100638029*45007#1 10000100647055*45007#1 10000100647299*45007#1 10000100800753*45007#1 10000100806036*45007#1 10000100813427*45007#1 10000100822318*45007#1 10000100822638*45007#1 10000100830454*45007#1 10000100835194*45007#1 10000100841890*45007#1 10000100847089*45007#1 10000100854782*45007#1 10000100858481*45007#1 10000100858863*45007#1 10000100868965*45007#1 10000100873980*45007#1 10000100875969*45007#1 10000100879221*45007#1 10000100879403*45007#1 
Thread Tools  
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Semiprime and nalmost prime candidate for the k's with algebra for the Sierpinski/Riesel problem  sweety439  sweety439  11  20200923 01:42 
Problem with prime 95 in worker #8  artesina  Information & Answers  5  20180227 20:51 
disk died, prime work lost forever? where to put prime? on SSD or HDD?  emily  PrimeNet  3  20130301 05:49 
Cullen prime problem  Citrix  Prime Cullen Prime  22  20070223 10:46 
Problem running primenet on debian (woody) dual processor  thedagit  Software  3  20021019 05:57 