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-   -   POST LOTS AND LOTS OF PRIMES HERE (https://www.mersenneforum.org/showthread.php?t=13180)

 rudy235 2020-01-20 07:33

[QUOTE=Thomas11;535508]283*2^6804731-1 (2048431 digits) :smile:[/QUOTE]

Great Start of the Year!

Last year (2019) we had to wait 60 days more to get a prime over 2 million digits.

 pepi37 2020-01-20 20:52

[QUOTE=Thomas11;535508]283*2^6804731-1 (2048431 digits) :smile:[/QUOTE]
Congratulations!

 storm5510 2020-02-02 01:07

1901*2^195870-1 is prime! (58967 decimal digits)

It is not much but it is a start, once I determined how to use [I]NewPGen[/I].

 VBCurtis 2020-02-02 07:10

[QUOTE=storm5510;536431]1901*2^195870-1 is prime! (58967 decimal digits)

It is not much but it is a start, once I determined how to use [I]NewPGen[/I].[/QUOTE]

You should use the "post small primes... here" thread for primes smaller than the top-5000 list cutoff, presently in the vicinity of 2^1.4M.

Also, newpgen is very very slow for this form of prime. The srsieve family of programs is an order of magnitude or so faster; srsieve to create the sieve initially, then sr1sieve to sieve a single "k" of k*2^n-1. If you're interested in multiple k's, sr2sieve is your hero.

sr1sieve speaks the same format as newpgen, so you can also use newpgen to create a sieve file, and then use sr1sieve to find factors. I forget if it's 10x or 20x faster, but it's really really fast. Command line, though- all the good stuff is, around here.

Have a look at [url]https://www.rieselprime.de/default.htm[/url] to see what primes are known for individual k's. For 1901, that's 2, 62, 66, 210, 290, 602, 726, 938, 998, 21342, 195870, 239030, 335018.

 storm5510 2020-02-02 14:38

[QUOTE=VBCurtis;536450]You should use the "post small primes... here" thread for primes smaller than the top-5000 list cutoff, presently in the vicinity of 2^1.4M...[/QUOTE]

Done. There has been no activity on that thread since 2017, until now.

[QUOTE=VBCurtis;536450]The srsieve family of programs is an order of magnitude or so faster; srsieve to create the sieve initially, then sr1sieve to sieve a single "k" of k*2^n-1. If you're interested in multiple k's, sr2sieve is your hero.

sr1sieve speaks the same format as newpgen, so you can also use newpgen to create a sieve file, and then use sr1sieve to find factors. I forget if it's 10x or 20x faster, but it's really really fast. Command line, though- all the good stuff is, around here.
[/QUOTE]

I would like to take a look at these. I will look around for them.

 paulunderwood 2020-02-06 02:47

[URL="https://primes.utm.edu/primes/page.php?id=130384"]69*2^6639971-1[/URL] is prime! (1998833 decimal digits) Time : 2777.921 sec.

This prime has taken many years for Vincent and me to find, but, oh boy, is it worth it!

:beer:

:party:

 diep 2020-02-06 08:02

[QUOTE=paulunderwood;536842][URL="https://primes.utm.edu/primes/page.php?id=130384"]69*2^6639971-1[/URL] is prime! (1998833 decimal digits) Time : 2777.921 sec.

This prime has taken many years for Vincent and me to find, but, oh boy, is it worth it!

:beer:

:party:[/QUOTE]

3x HURRAY!!!

 pinhodecarlos 2020-02-06 09:04

Congrats to both, well deserved.

 Thomas11 2020-02-06 09:45

Congratulations! :banana::banana::banana:

So close to 2 million decimal digits...

 diep 2020-02-06 09:54

If there is 1+ closeby we'll have it soon as well.

69 seems very unpredictable now because of the huge gap, yet odds are they group a little together.

 pepi37 2020-02-06 11:50

[QUOTE=diep;536869]If there is 1+ closeby we'll have it soon as well.

69 seems very unpredictable now because of the huge gap, yet odds are they group a little together.[/QUOTE]

What was last prime in that sequence?

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