20091119, 04:28  #1 
1976 Toyota Corona years forever!
"Wayne"
Nov 2006
Saskatchewan, Canada
2·11^{2}·19 Posts 
Awfully small factors....
Some recently turned in Manual Testing factors are under 40 bits???
Code:
GrunwalderGIMP Manual testing 128557967 F Nov 19 2009 2:11AM 0.0 0.0000 58879548887 GrunwalderGIMP Manual testing 128556863 F Nov 19 2009 2:11AM 0.0 0.0000 46280470681 GrunwalderGIMP Manual testing 128556803 F Nov 19 2009 2:11AM 0.0 0.0000 762341841791 They are listed, valid factors but how is it that such small factors are being turned in now? This range was likely factored to that level a 'long' time ago. 
20091119, 04:40  #2 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
3^{2}·7·149 Posts 
Ah, that's clear. These numbers already have aneven smaller factor, so for the search purposes they are eliminated. There used to be a configuration flag to report all factors or just one.
E.g. M128557967 has a factor: 31882375817 M128557967 has a factor: 58879548887 M128557967 has a factor: 10081001540273 M128556863 has a factor: 3085364713 M128556863 has a factor: 46280470681 M128556803 has a factor: 80219445073 M128556803 has a factor: 762341841791 
20091119, 04:46  #3 
P90 years forever!
Aug 2002
Yeehaw, FL
1110011101010_{2} Posts 
Ugh, a bug in prime95's factoring code? A computer glitch at the time that range was factored? Maybe some other program did that low level factoring?
Try seeing if prime95 will find those factors. If the problem is widespread, I'll have to do some statistical analysis to see what ranges need refactoring. 
20091119, 05:41  #4 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
3^{2}×7×149 Posts 
Someone used
SendAllFactorData=0 in prime.txt? 
20091119, 07:13  #5  
Sep 2006
Brussels, Belgium
3·7·79 Posts 
Looking at what is in the database for one of those exponents, one can only conclude that another program than Prime95 was used :
Exponent Date found Bits Factor 128557967 20071008 14:14 35 31882375817 128557967 20091119 02:11 36 58879548887 128557967 20091119 02:11 44 10081001540273 128557967 20091119 02:11 63 5171044349132734223 Even with the (undocumented in 25.11) SendAllFactorData option Prime95 would only continue looking for factors in one bit level : it would look for smaller factors than the first one found. Another possibility are multiple Factor lines for one exponent, instead from factor from 0 to 64 bits one line per bit level... Best thing would be to ask Gareth William or Grunwalder, the producer of those results. But his GIMPS referenced web page explains all : Quote:
Jacob Last fiddled with by S485122 on 20091119 at 07:18 Reason: corrected first name and added link 

20091119, 07:27  #6 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
3^{2}×7×149 Posts 
I also used to have a million factors submitted (with a small 64bit 40liner program), but now, a year had passed and they are gone from stats. I did submit multiples, though...

20091119, 14:56  #7  
1976 Toyota Corona years forever!
"Wayne"
Nov 2006
Saskatchewan, Canada
2·11^{2}·19 Posts 
Quote:


20091119, 15:03  #8 
1976 Toyota Corona years forever!
"Wayne"
Nov 2006
Saskatchewan, Canada
11F6_{16} Posts 
Prime95 25.9B4 wouldn't let me refactor it to lower levels than it currently is...
Code:
[Main thread Nov 19 09:01] Mersenne number primality test program version 25.9 [Main thread Nov 19 09:01] Starting workers. [Comm thread Nov 19 09:01] Registering assignment: Trial factor M128557967 [Comm thread Nov 19 09:01] URL: http://v5.mersenne.org/v5server/?v=0.95&px=GIMPS&t=ra&g=4f402bc7132e14b4bd6e989d4475e683&c=0&w=2&n=128557967&sf=20&ef=60&ss=959 [Comm thread Nov 19 09:01] RESPONSE: [Comm thread Nov 19 09:01] pnErrorResult=40 [Comm thread Nov 19 09:01] pnErrorDetail=ra: trial factoring not required, exponent: 128557967, ef: 60 [Comm thread Nov 19 09:01] ==END== [Comm thread Nov 19 09:01] [Comm thread Nov 19 09:01] PrimeNet error 40: No assignment [Comm thread Nov 19 09:01] ra: trial factoring not required, exponent: 128557967, ef: 60 [Comm thread Nov 19 09:01] Done communicating with server. 
20091119, 15:26  #9  
A Sunny Moo
Aug 2007
USA (GMT5)
6249_{10} Posts 
Quote:


20091119, 15:29  #10 
Einyen
Dec 2003
Denmark
2×5×307 Posts 
Prime95 25.11.2 finds them when factoring offline:
UID: athath/work2, M128557967 has a factor: 31882375817 UID: athath/work2, M128557967 has a factor: 58879548887 UID: athath/work2, M128557967 has a factor: 10081001540273 UID: athath/work2, M128556863 has a factor: 3085364713 UID: athath/work2, M128556803 has a factor: 762341841791 UID: athath/work2, M128556803 has a factor: 80219445073 But there is no "ContinueFactoring=1" command like the existing "ContinueECM=1", so its hard to find more factors without manually doing upper ranges. 
20091119, 17:27  #11  
Sep 2006
Brussels, Belgium
3×7×79 Posts 
Quote:
For the exponent I cited you can clearly see a 35 bits factor found in October 2007 and three LARGER factors found by Gareth (they may be larger but are still small at 36, 44 and 63 bits.) The 36 and 44 bits factors certainly qualify as awfully small factors for ranges that have already been factored to 63 bits. Jacob 

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