20041214, 14:55  #1 
Nov 2003
3·5·11 Posts 
Bad Factor?
I found this factor in the most recent data files (12/12/04):
24742121,3047713721183690569 k = 61589580804 3047713721183690569=53*1009*56991112462997 As 53 is clearly not of the form 2kp+1, 3047713721183690569 cannot divide M24742121. As the leading edge of factoring is at about 28.1M, I'm not sure where this faulty factor came from, and it does not appear in cleared.txt. I checked the 11/30/04 data files, and this factor was not there. Since I know factors are checked for both primality and correctness, I am a bit confused as to how this factor found its way into the data files. 
20041214, 15:40  #2 
Aug 2002
Termonfeckin, IE
3^{2}·307 Posts 
Yup! Looks like it is a bad factor. Wonder how it managed to get through.

20041214, 16:03  #3  
P90 years forever!
Aug 2002
Yeehaw, FL
11·673 Posts 
Quote:
and pasting from a DOS window loses the first few digits. Weird. Nice catch. 

20041214, 16:04  #4 
P90 years forever!
Aug 2002
Yeehaw, FL
7403_{10} Posts 
Msieve v. 0.86
random seeds: 000002bc 41bf0e6b factoring 555087078799770339769608793045705436436591887 Tue Dec 14 11:01:47 2004 using multiplier of 23 Tue Dec 14 11:01:47 2004 using sieve block of 65536 using a sieve bound of 19421 (1073 primes) using large prime bound of 776840 restarting with 721 full and 5356 partial relations found 1476 relations (721 full + 755 partial), need 1201 begin with 5356 relations reduce to 1399 relations in 2 passes attempting to read 721 full and 1399 partial relations recovered 721 full and 1399 partial relations recovered 620 polynomials attempting to build 755 cycles found 755 cycles in 1 passes distribution of cycle lengths: length 2 : 755 largest cycle: 2 relations Tue Dec 14 11:01:47 2004 1073 x 1137 system, weight 22284 (avg 19.60/col) reduce to 982 x 1046 in 3 passes lanczos halted after 17 iterations recovered 64 nontrivial dependencies Tue Dec 14 11:01:47 2004 probable prime factor: 20563047713721235292639 probable prime factor: 26994397257045406913233 Tue Dec 14 11:01:47 2004 
20041214, 16:19  #5  
Nov 2003
3·5·11 Posts 
Quote:


20041214, 17:44  #6  
Banned
"Luigi"
Aug 2002
Team Italia
17·283 Posts 
Quote:
I found out that cutting and pasting from a dos window leaves part of the digits of the long factor in the next line. I need to import the screenshot into wordpad and realign the number (usually deleting the carriage return char) before using it. Luigi 

20041214, 19:25  #7  
Bamboozled!
"πΊππ·π·π"
May 2003
Down not across
29·367 Posts 
Quote:
You describe an irritating feature of Windows C&P. It works on what's displayed on the screen rather than the underlying semantic object. If it looks like two words on two separate lines, Windows C&P treats it as such, even if it came from a singe word. Most X11based tools treat a single word as a single entity, whether or not it appears on one line or several. Paul 

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