20180712, 17:22  #1 
Bemusing Prompter
"Danny"
Dec 2002
California
2×3×397 Posts 
Mersenne.ca discrepancies
I recently noticed a few discrepancies with the Mersenne.ca database:
1. The entry for M87940961 shows that the minimum P1 bounds are not calculated. I haven't seen this for any other exponent. Is there any reason for this? 2. The entry for M25153 incorrectly lists 95798344469709111399327318847787476387212693634994913715944997998172541010266957318247461159 as a prime factor. It's actually the product of the four currently known factors. 
20180712, 23:35  #2  
Oct 2017
++41
5^{3} Posts 
Quote:
https://www.mersenne.org/report_expo...exp_hi=&full=1 

20180721, 17:27  #3 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
9,431 Posts 
Same thing appears to be happening in
http://www.mersenne.ca/exponent/7508981 Code:
196390556749512365885553091471517315772448332119011812799224967043247355807885758998536981636538241093908075798179275216900756503990104076135107768463 is not a prime factor Code:
2483611811780967729450526041810356652852620293014220023255782117303084384090070203366756119 97741873979710938487033764107284665796924065785506374732657395204556552490513667177770940383463688455655450791 92931654532319876438832186923672422729542099694851688102212583901293792387759635634014037818755101113436948191796372627855844302598713 are not prime factors 
20180721, 23:08  #4  
"James Heinrich"
May 2004
exNorthern Ontario
3,361 Posts 
Quote:
Quote:
Quote:


20180722, 02:35  #5 
P90 years forever!
Aug 2002
Yeehaw, FL
2^{2}·1,873 Posts 
Even a one or two thousand bit PRP test should be pretty near instantaneous. Alternatively, attempting to divide by known factors would be very quick. Once setup, it would save you from manually handling big composites.

20180722, 02:50  #6 
"James Heinrich"
May 2004
exNorthern Ontario
3361_{10} Posts 
Both fair points. I'll see if I can work those ideas into the codeflow.

20180803, 17:16  #7  
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
10010101100110_{2} Posts 
Quote:
Seems to be a problem in the code. Email/pm will be sent. 

20180803, 21:04  #8 
"James Heinrich"
May 2004
exNorthern Ontario
3,361 Posts 
I think I see what you're getting at. If you copypaste the exponent with other characters in it (e.g. "M79,777,211") into the exponent field it would first limit the input to 9 characters, then remove the nonnumeric characters, leaving you with a truncated value. I have removed the input length limit so it should work as expected now.

20180803, 21:40  #9 
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
2×4,787 Posts 

20201031, 05:14  #10 
Jun 2003
4962_{10} Posts 

20201031, 11:40  #11  
"James Heinrich"
May 2004
exNorthern Ontario
3361_{10} Posts 
Quote:


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