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.

Largest prime for 2020 (till now)
 

TO BE VERIFIED

Congratulations to Serge Batalov.

Gaussian Mersenne. #20 on the current list.

2[SUP]15317227[/SUP] + 2[SUP]7658614[/SUP] + 1

4,610,945 digits.

[QUOTE=rudy235;552206]TO BE VERIFIED

Congratulations to Serge Batalov.

Gaussian Mersenne. #20 on the current list.

2[SUP]15317227[/SUP] + 2[SUP]7658614[/SUP] + 1

4,610,945 digits.[/QUOTE]


Serge never publish prime until he is 101% sure it is prime :)

[QUOTE=pepi37;552218]Serge never publish prime until he is 101% sure it is prime :)[/QUOTE]

Well, 101 happens to be prime.

Congrats to Scott Brown for the "321+" prime, [URL="https://primes.utm.edu/primes/page.php?id=131362"]3*2^16408818+1[/URL], which was 6.5 years in the making by PrimeGrid.

:banana:

Seems a new prime for the [url='https://www.rieselprime.de/ziki/Riesel_problem']Riesel Problem[/url] was found: [url='https://primes.utm.edu/primes/page.php?id=131405']146561*2^11280802-1[/url] found by PrimeGrid's project currently in verify status.
This is, when proven, almost 3 years after the last found for this problem.

"P587124"
 

Congrats to a1call for [URL="https://primes.utm.edu/primes/page.php?id=131431"]this top5000 prime[/URL] of a most unusual construction.

:banana:

[QUOTE=kar_bon;563554]Seems a new prime for the [url='https://www.rieselprime.de/ziki/Riesel_problem']Riesel Problem[/url] was found: [url='https://primes.utm.edu/primes/page.php?id=131405']146561*2^11280802-1[/url] found by PrimeGrid's project currently in verify status.
This is, when proven, almost 3 years after the last found for this problem.[/QUOTE]

this number is now proven to be prime, now there are 47 Riesel base 2 candidate left.

[QUOTE=sweety439;564956]this number is now proven to be prime, now there are 47 Riesel base 2 candidate left.[/QUOTE]

No, that page was already updated: there're still 48 k-values left.

New 1.43M repdigit prime will appear soon :)
It was time to find something bigger after 5 years searching in this sequence :)

Good! Congratulations!