[QUOTE=chris2be8;396649]Is anyone working on the PRP in post 204?[/QUOTE]

It's had a certificate submitted which factordb is processing. Thanks to whoever submitted if.

Chris

[URL="http://factordb.com/index.php?id=1100000000762116112"]Phi(5,-205*2^771)[/URL]
Note that N-1 is divisible by 205*2^771 and by 205*2^771-1 which is prime.

Similar proofs are possible for Phi[SUB]7[/SUB](n) and Phi[SUB]15[/SUB](n) (with CHG and some extra factoring).
Maybe some [URL="http://factordb.com/index.php?query=%28%282%5E96*173%29%5E11%2B1%29%2F%282%5E96*173%2B1%29"]Phi[SUB]11[/SUB](n)[/URL]...?

If anyone wants a challenge proving [url]http://factorization.ath.cx/index.php?id=1100000000260577719[/url] (3747 digits) is prime will enable a N+1 proof for [url]http://factorization.ath.cx/index.php?id=1100000000295827426[/url] (17^3564+16) (that's 4386 digits).

Chris

[QUOTE=chris2be8;396892]If anyone wants a challenge proving [URL]http://factorization.ath.cx/index.php?id=1100000000260577719[/URL] (3747 digits) is prime will enable a N+1 proof for [URL]http://factorization.ath.cx/index.php?id=1100000000295827426[/URL] (17^3564+16) (that's 4386 digits).

Chris[/QUOTE]

Not a very big challenge. Even the single threaded windows version of primo will do this overnight.

Here's an easier case. Proving [URL]http://factorization.ath.cx/index.php?id=1100000000762583206[/URL] (300 digits) should enable a N-1 proof for [URL]http://factorization.ath.cx/index.php?id=1100000000439186872[/URL] ((316^1801-1)/315).

Chris

PS. What is the practical limit for PRIMO proofs?

[QUOTE=chris2be8;396940]
PS. What is the practical limit for PRIMO proofs?[/QUOTE]

35k digits for the latest Linux implementation, running at O(log(n)^(4+eps)). 300 digits takes a minute or two on a multicore system I guess :smile:

[QUOTE=paulunderwood;396941]35k digits for the latest Linux implementation, running at O(log(n)^(4+eps)). 300 digits takes a minute or two on a multicore system I guess :smile:[/QUOTE]
IIRC a 300 digit PRP took a few seconds on a single core in Windows.

I'm usually downloading the lower PRPs (<= 1000 digits) in batches of 100 and give them to primo using 2 Threads on my 5 year old Athlon II X2 250. The smaller ones are done within seconds the larger ones take around 2 minutes or so. The only limitation here is primo which can't be automated to work with a script. So there is still some manual work required which usually stops me from working on the smaller PRPs.

[QUOTE=ChristianB;396954]I'm usually downloading the lower PRPs (<= 1000 digits) in batches of 100 and give them to primo using 2 Threads on my 5 year old Athlon II X2 250. The smaller ones are done within seconds the larger ones take around 2 minutes or so. The only limitation here is primo which can't be automated to work with a script. So there is still some manual work required which usually stops me from working on the smaller PRPs.[/QUOTE]

Marcel said he would make Primo command line driven once he has made stable his code. :smile:

[QUOTE=paulunderwood;396955]Marcel said he would make Primo command line driven once he has made stable his code. :smile:[/QUOTE]

Then I would like to run it in a Boinc project :)

[QUOTE=ChristianB;396954]I'm usually downloading the lower PRPs (<= 1000 digits) in batches of 100 and give them to primo using 2 Threads on my 5 year old Athlon II X2 250. The smaller ones are done within seconds the larger ones take around 2 minutes or so. The only limitation here is primo which can't be automated to work with a script. So there is still some manual work required which usually stops me from working on the smaller PRPs.[/QUOTE]

I think the maximum number of tests you can start at once is 999, maybe that helps reducing the amount of manual work.