mersenneforum.org (https://www.mersenneforum.org/index.php)
-   Sierpinski/Riesel Base 5 (https://www.mersenneforum.org/forumdisplay.php?f=54)
-   -   S/R Base 5 Primes reported in 2017+ (https://www.mersenneforum.org/showthread.php?t=23446)

 TheCount 2018-06-16 08:04

S/R Base 5 Primes reported in 2017+

Congratulations to Frank Schwegler for finding the 1st SR5 prime of 2017.
The prime 171362*5^2400996-1 found on 25 August 2017 eliminates k=171362 from the base 5 Riesel problem. The prime is 1,678,230 digits long and entered Chris Caldwell's “The Largest Known Primes Database” ([URL]http://primes.utm.edu/primes[/URL]) ranked 57th overall. 73 k's then remained in the Riesel Base 5 Problem.

Congratulations to Håkan Lind for finding the 2nd SR5 prime of 2017.
The prime 301562*5^2408646-1 found on 17 September 2017 eliminates k=301562 from the base 5 Riesel problem. The prime is 1,683,577 digits long and entered Chris Caldwell's “The Largest Known Primes Database” ([URL]http://primes.utm.edu/primes[/URL]) ranked 57th overall. 72 k's now remain in the Riesel Base 5 Problem. The base 5 Sierpinski problem has 33 k's remaining.

Primegrid is currently running a 5 day challenge on the Sierpinski / Riesel Base 5 (SR5) project, ends 19th June 2018 00:00 UTC.
For details, please read the post in the PrimeGrid forum:

 pepi37 2018-06-19 19:44

And new prime in this class is fall!

 pepi37 2018-06-22 13:03

And another one :)
After long time two primes in difference of few days.

 TheCount 2018-06-24 05:22

S/R Base 5 Primes reported in 2018

Congratulations to Selya Tsuji for finding the 1st SR5 prime of 2018.
The prime 327926*5^2542838-1 found on 19 June 2018 eliminates k=327926 from the base 5 Riesel problem. The prime is 1,777,374 digits long and entered Chris Caldwell's “The Largest Known Primes Database” ([URL]http://primes.utm.edu/primes[/URL]) ranked 60th overall. 71 k's now remain in the Riesel Base 5 Problem.

Congratulations to Jiří Bočan for finding the 2nd SR5 prime of 2018.
The prime 81556*5^2539960+1 found on 20 June 2018 eliminates k=81556 from the base 5 Sierpinski problem. The prime is 1,775,361 digits long and entered Chris Caldwell's “The Largest Known Primes Database” ([URL]http://primes.utm.edu/primes[/URL]) ranked 61st overall. 32 k's now remain in the Sierpinski Base 5 Problem.

Both of these primes were found just after the Primegrid SR5 challenge.

 DukeBG 2018-06-25 11:27

To be pedantic, both workunits were sent out [i]during[/i] the challenge :)

 TheCount 2018-08-05 01:18

S/R Base 5 Primes reported in 2018

Congratulations to Honza Cholt for finding the 3rd SR5 prime of 2018.
The prime 66916*5^2628609-1 found on 29 July 2018 eliminates k=66916 from the base 5 Riesel problem. The prime is 1,837,324 digits long and entered Chris Caldwell's “The Largest Known Primes Database” ([URL]http://primes.utm.edu/primes[/URL]) ranked 59th overall. 70 k's now remain in the Riesel Base 5 Problem.

 TheCount 2018-09-16 01:10

S/R Base 5 Prime reported in 2018

Congratulations again to Honza Cholt for finding the 4th SR5 prime of 2018.
The prime 194368*5^2638045-1 found on 15 August 2018 eliminates k=194368 from the base 5 Riesel problem. The prime is 1,843,920 digits long and entered Chris Caldwell's “The Largest Known Primes Database” ([URL]http://primes.utm.edu/primes[/URL]) ranked 60th overall. 69 k's now remain in the Riesel Base 5 Problem.

 pepi37 2019-04-27 07:33

And we have new SR5 prime!

[B][URL="http://primes.utm.edu/primes/page.php?id=126425"]138514*5^2771922+1[/URL][/B] found by Ken Ito on 26 April 2019

1937496 digits, position 63

 unconnected 2019-04-27 10:23

[QUOTE=pepi37;514878]And we have new SR5 prime!

[B][URL="http://primes.utm.edu/primes/page.php?id=126425"]138514*5^2771922+1[/URL][/B] found by Ken Ito on 26 April 2019

1937496 digits, position 63[/QUOTE]
Wow! I'm the doublechecker for this prime on Primegrid. :cool:

 pepi37 2019-04-27 18:04

[QUOTE=unconnected;514899]Wow! I'm the doublechecker for this prime on Primegrid. :cool:[/QUOTE]
Use -t option and be faster next time!

 pepi37 2019-06-21 18:12

And new one is arrived :)

[URL]https://primes.utm.edu/primes/page.php?id=126564[/URL]

88444 · 5^2799269 - 1

All times are UTC. The time now is 11:16.