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Old 2020-07-13, 22:48   #210
carpetpool
 
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Nov 2016

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Another lucky hit:

26*3^1700041+1 may be prime, but N divides 3^((N-1)/3))-1, restarting with a=5 Time : 938.494 sec.
26*3^1700041+1 is prime! (811128 decimal digits) Time : 946.942 sec.
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Old 2020-08-01, 17:44   #211
rudy235
 
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Default Largest prime for 2020 (till now)

TO BE VERIFIED

Congratulations to Serge Batalov.

Gaussian Mersenne. #20 on the current list.

215317227 + 27658614 + 1

4,610,945 digits.
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Old 2020-08-01, 20:16   #212
pepi37
 
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After milion nines:)

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Quote:
Originally Posted by rudy235 View Post
TO BE VERIFIED

Congratulations to Serge Batalov.

Gaussian Mersenne. #20 on the current list.

215317227 + 27658614 + 1

4,610,945 digits.

Serge never publish prime until he is 101% sure it is prime :)
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Old 2020-08-02, 17:36   #213
rudy235
 
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Quote:
Originally Posted by pepi37 View Post
Serge never publish prime until he is 101% sure it is prime :)
Well, 101 happens to be prime.
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Old 2020-10-30, 22:13   #214
paulunderwood
 
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Congrats to Scott Brown for the "321+" prime, 3*2^16408818+1, which was 6.5 years in the making by PrimeGrid.

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Old 2020-11-17, 21:06   #215
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Seems a new prime for the Riesel Problem was found: 146561*2^11280802-1 found by PrimeGrid's project currently in verify status.
This is, when proven, almost 3 years after the last found for this problem.
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Old 2020-12-01, 17:46   #216
paulunderwood
 
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Thumbs up "P587124"

Congrats to a1call for this top5000 prime of a most unusual construction.

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Old 2020-12-01, 19:05   #217
sweety439
 
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Quote:
Originally Posted by kar_bon View Post
Seems a new prime for the Riesel Problem was found: 146561*2^11280802-1 found by PrimeGrid's project currently in verify status.
This is, when proven, almost 3 years after the last found for this problem.
this number is now proven to be prime, now there are 47 Riesel base 2 candidate left.
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Old 2020-12-01, 23:49   #218
kar_bon
 
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Quote:
Originally Posted by sweety439 View Post
this number is now proven to be prime, now there are 47 Riesel base 2 candidate left.
No, that page was already updated: there're still 48 k-values left.
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Old 2020-12-11, 23:32   #219
pepi37
 
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After milion nines:)

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New 1.43M repdigit prime will appear soon :)
It was time to find something bigger after 5 years searching in this sequence :)
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Old 2020-12-11, 23:43   #220
Batalov
 
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Mar 2008
Phi(4,2^7658614+1)/2

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Good! Congratulations!
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