Pascal's OPN roadblock files

[henryzz]

Originally Posted by swellman

I think you can use higher TD, say 90 or 100, but as this job is on the low end of the difficulty spectrum it probably isn’t worth rerunning several times to optimize the matrix size/density and time to solve.

237M for your target number of relations seems high - the mean of the target # rels for 31 and 30 respectively is best for a target # rels for a 31/30 job. Say 190-200M, i.e. (135M+260M)/2.

The usual practice for requesting a 14d job is to post it in this thread.

You can request download credentials from Greg, but if this is a one off then you just rely on a volunteer to run the LA. If no one else steps up I can do it.

Sounds like the sieve region should be altered to 40M-100M. This reduces the estimated relations to 204M. This is still on the high side but I have read large quartics have a higher dup rate.

[Happy5214]

Originally Posted by Pascal Ochem

Thank you!
You might get more hits with this list of composites
https://www.lirmm.fr/~ochem/opn/bound_on_m.txt
They appear in the proof that \(m > 10^{950}\), where \(OPN=p^em^2\)

Originally Posted by Happy5214

Will try, thanks!

Just to update this search... I started with a random shuffle, doing a t30 plus half-a-t35 on each one. I did about 40-ish lines that way, finding 15 factors, and I noticed that most of the factors (12/15) were found with B1=250K or less. I then decided to go from start to finish, doing just under a t30 (yafu is weird about its curve count rounding). I've found a ton of factors doing that through the first 165 lines. In total, I've completely factored six composites and found 63 ECM/P-1 factors so far. I'm trying to post everything to FactorDB as I go.

[henryzz]

Factoring 1528152860898312226820507829734311038694803153043007 ^ 5 - 1 has reduced the proof for 13^4 to 2500 to a third of its previous size(15.6M stat_rec vs 46.4M stat_rec).
Currently have 7/15 of the forbidden primes to 2500. 3 or 4 are nearly there. I believe the first four (127, 19, 7, 11) are going to be the hard ones.

[Happy5214]

Originally Posted by Pascal Ochem

Thank you!
You might get more hits with this list of composites
https://www.lirmm.fr/~ochem/opn/bound_on_m.txt
They appear in the proof that \(m > 10^{950}\), where \(OPN=p^em^2\)

OK, I just finished testing all of these candidates to just under a t30 (that's a t25 + 404 curves @ B1=250K; yafu's rounding was previously mentioned). I eliminated 46 candidates from the list and found a few hundred additional factors (honestly, I lost count). Rather than parse the yafu output, I dumped them into FactorDB as I was going, so you can find them there.

[SuikaPredator]

Trying to hit bound_on_m.txt with 900 curves @1e6. (In random order)

Found 7 factors out of first 24 composites, uploaded them to factordb, pretty satisfactory success rate.

[Happy5214]

Originally Posted by SuikaPredator

Trying to hit bound_on_m.txt with 900 curves @1e6. (In random order)

Found 7 factors out of first 24 composites, uploaded them to factordb, pretty satisfactory success rate.

I posted all of my factors to FactorDB, so make sure you check there before running a number to avoid duplication.

Edit: Alternatively, I've attached the yafu input of what was left over from my run, which you can just use as stdin.

[SuikaPredator]

Originally Posted by Happy5214

I posted all of my factors to FactorDB, so make sure you check there before running a number to avoid duplication.

Edit: Alternatively, I've attached the yafu input of what was left over from my run, which you can just use as stdin.

Thanks for your status update, I will try to eliminate candidates using the file you uploaded.

[henryzz]

Does anyone have an automated way of checking for OPN factors from the factordb?

[RichD]

Originally Posted by henryzz

Does anyone have an automated way of checking for OPN factors from the factordb?

Pascal has something he uses based on this post.

[lavalamp]

I have found that factor db will sometimes show different factorisations depending if one looks up b^n-1 or (b^n-1)/(b-1). I assume that sometimes in the backend (b^n-1)/(b-1) is not always linked as a factor of b^n-1, or perhaps that changes to one page may take a while to propogate to another.

Since I noticed that I've always made sure to report factors to both pages to ensure that they aren't missed.

[Pascal Ochem]

The run to prove \(m\ge 10^{1000}\) finished without problems a few weeks ago.

Originally Posted by RichD

Pascal has something he uses based on this post.

I have asked skilled people to write suitable scripts, back in the days. If the file comp contains composites in tXXX format, the command
toto.sh comp
produces the files comp_f containing the factors in checkfacts format and comp_n containing the remaining composites.

toto.sh:

#!/bin/bash
oddfactors.pl $1
fhtml=$$_html
furl=$$_url
touch $1factors.html
for i in $(cat $1factors.html | sed 's/<\/p>/X/g' | tr "X" "\n" | sed -e "s/<p>.*='//" -e "s/'.*//g")
do
    wget $i -O $fhtml 2>/dev/null 1>&2
    echo $(cat $fhtml | tr ">" "\n" | grep index.php? | grep -v show | head -2 | tail -1 | sed -e 's/.*="//' -e 's/"//') >> $furl
    echo -n "."
done
echo
touch $furl
for i in $(cat $furl)
do
    wget factordb.com/$i -O $fhtml 2>/dev/null 1>&2
    echo $(cat $fhtml | grep value | head -1 | sed -e 's/.*value="//' -e 's/">//') >> $$_factor.txt
    echo -n "."
done
echo
rm $fhtml

match $1 $$_factor.txt > $1_f
rm $furl $1factors.html $$_factor.txt
date

oddfactors.pl:

#!/bin/sh
#! -*-perl-*-
eval 'exec perl -x -wS $0 ${1+"$@"}'
if 0;
use strict;
use warnings;
use LWP::Simple;
use vars qw/$line @line $page $data $file/;

open (IN, $ARGV[0]) || die " cannot open file";
open (LEFT,">${ARGV[0]}_n");
$file="$ARGV[0]factors.html";
open (OUT,">$file");

my $i=0;
my $j=0;
while (defined($line=<IN>))
{
        chomp $line;
        @line= split /\s/,$line;
        #print OUT "$line[2]\n";
        $page="http://factordb.com/index.php?query=$line[2]";
        $data=get($page);

        if ($data =~ m/\<td\>FF\<\/td\>/ || $data =~ m/\<td\>CF\<\/td\>/ ) 
        {
                #print OUT "$line is factored!\n\t$page\n":
                print OUT "<p><a href='$page'>$line[0] $line[1] is factored!</a></p>";
                $i++;
        }
        else 
        {
                print LEFT "$line\n";
                $j++;
        }
}
close IN;
close OUT;
if (-z $file)
{
        print "No numbers factored\n"
}
else {print "Factored $i\nRemaining $j\n";}