20040903, 10:15  #1 
Jun 2004
2^{2} Posts 
largest factor ,i think.
i found a largest factor of M65536 i think ,what to do next.
please help me,thanks. 
20040903, 11:30  #2  
Banned
"Luigi"
Aug 2002
Team Italia
4857_{10} Posts 
Quote:
BTW, what program did you use, and which factor did you find? Luigi Last fiddled with by ET_ on 20040903 at 11:31 

20040903, 11:43  #3  
"Bob Silverman"
Nov 2003
North of Boston
2×3^{3}×139 Posts 
Quote:
factors M65536 = M32768 * P32768 = M16384 * P16384 * P32768 = M8192 * P8192 * P16384 * P32768 = ... etc. etc..... Now If you are claiming a new factor of F15 or F14 etc., that would be noteworthy! 

20040903, 12:02  #4  
"William"
May 2003
Near Grandkid
4505_{8} Posts 
Quote:
To read Will's files you need to understand about algebraic factors. In your case this is simple. 2^{65536}1 factors into (2^{32768}+1) (2^{16384}+1) (2^{8192}+1) (2^{4096}+1) etc. Note that Will lists the factors of (2^{k}+1) under M(2k). Some of the known factors are: M( 65536 )C: 4659775785220018543264560743076778192897 M( 65536 )C: 7455602825647884208337395736200454918783366342657 M( 16384 )C: 319546020820551643220672513 M( 8192 )C: 1256132134125569 When your number is less the 10,000 digits, you can use Dario Alpern's Java Applet to look up the known factors. Dario regularly gets the latest factor files from Will Edgington and Richard Brent. While your number is too large, the two "top level" factors of (2^{32768}+1) and (2^{32768}1) fit. If your factor is new, then send Will Edgington an email and it will appear in the next release of his files. Then brag a little bit. Here and the Yahoo PrimeNumbers list are good places to brag. William 

20040904, 10:12  #5 
Jun 2004
2^{2} Posts 
it is 148 digits .

20040904, 18:51  #6  
Banned
"Luigi"
Aug 2002
Team Italia
3×1,619 Posts 
Quote:
384 bits? Luigi 

20040904, 23:25  #7  
Mar 2003
New Zealand
485_{16} Posts 
Quote:
If so and you found it with Prime95 then make sure you have a copy of http://www.mersenne.org/gimps/lowm.txt in Prime95's working directory to avoid finding already known factors in the future. (If not, then congratulations!) 

20040905, 05:11  #8  
"William"
May 2003
Near Grandkid
3·7·113 Posts 
Quote:
http://www.alpertron.com.ar/ECM.HTM 

20040906, 01:49  #9  
Mar 2003
New Zealand
13·89 Posts 
Quote:


20040907, 20:12  #10 
"Phil"
Sep 2002
Tracktown, U.S.A.
2^{5}·5·7 Posts 
Does your 148digit factor end in a 5? If so, you have found a 148digit composite which is probably a product of known factors of Fermat numbers. Factor your number using Dario Alpern's factoring applet and then check the factors listed at:
http://www.prothsearch.net/fermat.html If you found this factor using Prime95, download lowm.txt first. 
20040908, 11:15  #11  
Jun 2004
2^{2} Posts 
Quote:
thanks for you all . 

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