20190623, 21:56  #1 
Sep 2002
Database er0rr
DCC_{16} Posts 
Te$ting billion digit number$
With the EFF award in mind, I am running this program:
Code:
forprime(q=1,100000000000,s=Mod(1416317954,q);for(k=7,33,s=s^22;if(s==2,print([q,k2]);break))) [2, 5] [3, 5] [7, 5] [31, 5] [97, 5] [127, 7] [607, 5] [8191, 13] [12289, 10] [22783, 8] [131071, 17] [265471, 8] [524287, 19] [592897, 8] [1310719, 18] [21757951, 18] [29687809, 14] [39845887, 21] [665972737, 10] [708158977, 6] [2147483647, 31] [2210398207, 22] [2543310079, 8] [58133053441, 23] [60651732991, 21] (Note that 97 is there because k starts at 7.) Last fiddled with by paulunderwood on 20190623 at 22:09 
20190623, 22:29  #2 
Sep 2003
3^{2}×7×41 Posts 

20190623, 23:26  #3 
"Rashid Naimi"
Oct 2015
Remote to Here/There
1981_{10} Posts 
This thread reminds me of a very old SciFi novel that I never read myself but was told about by a friend:
Person A: They have spaceships that can travel to the Moon. Person B: That's impossible. The power required for such a trip is enormous. Person A: Yes, but they are using steamengines to power their ships. Last fiddled with by a1call on 20190623 at 23:27 
20190623, 23:54  #4  
If I May
"Chris Halsall"
Sep 2002
Barbados
2×3×1,567 Posts 
Quote:
I fail to understand why SETI listens for lowband microwaves when higher frequency photons are more likely to be used for long distant communications. Maybe I'm just stupid. A nonzero probably. 

20190624, 00:39  #5 
"Rashid Naimi"
Oct 2015
Remote to Here/There
7·283 Posts 
At the risk of further off tracking, I agree that SETI is based on assuming the ET to have mastered capabilities that we did not possess a mere 200 years ago such as radio communication as well as AmplitudeModulation which is only one of the many different possibilities of using electromagnetic waves, Yes there are more probable means than used by SETI. But that's a CanofWorms best left unopened in a WikipediaObsessed, DemocraticallyDictatedScience, audience.

20190624, 01:24  #6 
Sep 2002
Database er0rr
2^{2}·883 Posts 
One more datum:
Code:
[87075848191, 21] 
20190624, 06:09  #7 
Sep 2002
Database er0rr
2^{2}·883 Posts 
Code:
? p=58133053441;for(k=1,1000000000,if(Mod(2,2*k*p+1)^p==1,print(k))) ? ## *** last result computed in 25min, 51,820 ms. 
20190624, 06:30  #8 
"Robert Gerbicz"
Oct 2005
Hungary
1,429 Posts 

20190624, 06:43  #9  
Apr 2019
5·41 Posts 
Quote:
already and no factors. Your code above is up to ~66.6bits Code:
? log(2*1000000000*58133053441+1)/log(2) %1 = 66.655992491035654326600824278847640961 Last fiddled with by hansl on 20190624 at 07:09 

20190624, 07:16  #10 
Sep 2002
Database er0rr
2^{2}·883 Posts 
I am testing 76 to 77 bits

20190624, 07:27  #11 
Apr 2019
205_{10} Posts 
OK, i'm ~70% done with 7576. And I've started 7778 and 7879 on other boxes.
BTW, I can't wait to upgrade one of my workstations. I recently ordered parts to take it from 6C/12T up to (dual socket) 24C/48T ... 4x the cores edit: No Factor from 7576 bits. Last fiddled with by hansl on 20190624 at 07:46 
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