20200105, 08:05  #1 
Oct 2019
1_{2} Posts 
I want to factor the cofactor of M1213(Cunningham 2,1213) in NFS@Home.
I want to factor the cofactor of M1213(Cunningham 2,1213) in NFS@Home.

20200105, 10:43  #2  
Jun 2015
Vallejo, CA/.
2^{2}×239 Posts 
Quote:
Code:
TwentyFour More Wanted: 2,1213 C297 2,1019+ C223 2,1934M C225 2,1954M C246 2,1982M C249 3,619 C207 3,619+ C272 3,631+ C219 5,431 C266 5,424+ C282 5,431+ C292 6,391 C274 6,389+ C242 6,391+ C260 7,356+ C207 10,323 C271 10,302+ C289 10,304+ C282 10,311+ C223 11,292+ C259 12,271 C234 12,277 C285 12,271+ C250 12,274+ C213 

20200105, 11:02  #3  
Nov 2003
1D19_{16} Posts 
Quote:
There are Cunningham numbers that have been waiting ~60 years to be factored. What is special about this one? It is not even the first hole in its table. And, if you have been paying attention, you would notice that it is ~128 bits larger than the largest number sieved so far by NFS@Home. That number took 6 weeks to sieve. I suggest that you estimate how long M1213 would take. Estimate the required memory for the LA while you are at it. There are a lot of numbers that I would like to factor. It doesn't mean that it is possible to do so. 

20200105, 17:24  #4  
"Curtis"
Feb 2005
Riverside, CA
11·383 Posts 
Quote:
If you mean that you want to factor it yourself, Amazon has the hardware you need, right at your fingertips. 33bit large primes are not optimal, one reason this number is better done outside NFS@home. Good luck! 

20200105, 18:41  #5  
Nov 2003
3·13·191 Posts 
Quote:
factor bases. It will probably need 35 or 36 bit large primes with three on each side. This would necessitate a rebuilding of the NFS@Home client, as well as significantly more memory per client core. This, in turn, will sharply reduce the number of available cores because many machines will not have enough memory. A very rough estimate of the required sieve time gives about 7 to 8 years, assuming no loss of resources due to memory requirements. [every 6 to 7 digit increase doubles the run time]. OTOH Amazon will have many more cores to run the client. I would be quite pleased to see this number factored. Go for it! I suggest running a t75 ECM effort first. t65 has been run. 

20200105, 19:08  #6  
Nov 2003
16431_{8} Posts 
Quote:
why he/she thinks this number warrants special attention. 

20200106, 04:40  #7  
"Dylan"
Mar 2017
2^{2}·11^{2} Posts 
Quote:
1. He has the resources to do it, and he's announcing his intentions (but in that case it would probably be better to contact Wagstaff himself), or 2. He's got a "new" way to factor numbers, which would most likely be debunked and he'd be labelled as a crank. 

20200106, 05:07  #8  
Nov 2003
1D19_{16} Posts 
Quote:
to reply to a legitimate question: What is special about this number? He might also come back because he genuinely wants to learn the details. 

20200106, 05:41  #9 
"Carlos Pinho"
Oct 2011
Milton Keynes, UK
4595_{10} Posts 
Same post on here: https://escatter11.fullerton.edu/nfs...ead.php?id=763

20200109, 00:22  #10  
Nov 2003
16431_{8} Posts 
Quote:
The least the OP could do is show a little courtesy by responding to my question about why the number is important. Or is he just going to post then vanish? 

20200109, 02:57  #11 
Jun 2003
2^{3}·3·193 Posts 
There is a notinsignificant probability that OP is a spammer who chose a semiplausible first post to get thru moderation. I suggest you all ignore this thread until such time as OP comes back with an appropriate response.

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