OddPerfect enthusiasts & others: ECM help needed!
 

NFS@Home is working its way up in difficulty toward a kilobit SNFS. We're at 285 digits now, and in about 1-2 months we will start a 290 digit number. sigma(3^606) = 3,607- is a very attractive number since it's simultaneously an OddPerfect roadblock, Cunningham 5th hole once the 3- extension is added (and 3,563- is finished, which will happen shortly), and a number with no known nontrivial factors. We would appreciate any help the OP community and others can provide. For now, the number needs more ECM. Currently a bit over 1*t55 has been completed, so it needs curves with B1 = 26e7.

The easiest way is to create a file containing the line

(3^607-1)/2

then run the command

ecm -c 10 26e7 < file.txt

Adjust 10 to the number of curves you wish to run. Just report the number of curves you have completed in this thread, and thanks in advance for any help you can provide!
[I]
All curves are included in the ECM Server at oddperfect.no-ip.com:8201[/i]
[code]Post# Curves
4 10
20 40
28 4
36 1
41 15
46 224
49 3100 included in #72
53 320
57 3
72 3508 included in ECM Server
73 3393 new in ECM Server
74 240
75 10
76 960
77 6703
87 883
89 4594
[/code]
[i]Including directly reported curves, the ECM Server stands at 23785

including lower ECM curves (13875@43e6 & 18240@11e7), this is [B]4.90 t55[/B] or [B]0.96 t60[/B][/i]

[QUOTE=frmky;225800]
The easiest way is to create a file containing the line

(3^607-1)/2

then run the command

ecm -nn -c 10 26e7 < file.txt

Adjust 10 to the number of curves you wish to run. Just report the number of curves you have completed in this thread, and thanks in advance for any help you can provide![/QUOTE]

I would suggest a command line like

ecm [B]-nn[/B] -c 10 26e7 <file.txt [B]>>outputfile.out[/B]

with the -nn flag, ecm will run on lowest priority.

">>outputfile.out" redirects the output to an outputfile and thus prevents from data loss when a factor is found and the command line window (or bash window) is accidently closed (or the computer crashes for some reason).

If the PC is short on RAM, the command line flag -maxmem <number of MB to use> can be used. For example, -maxmem 500 uses not more than 500 MB RAM.

I will run a fistful of curves until my next GNFS (from aliquot sequence 10212) takes my ressources for a while.

[quote=Andi47;225814]I would suggest a command line like

ecm [B]-nn[/B] -c 10 26e7 <file.txt [B]>>outputfile.out[/B]

with the -nn flag, ecm will run on lowest priority.

">>outputfile.out" redirects the output to an outputfile and thus prevents from data loss when a factor is found and the command line window (or bash window) is accidently closed (or the computer crashes for some reason).[/quote]
Even better, if you're on Linux (or Windows w/Cygwin):

./ecm -nn -c 10 26e7 < file.txt | tee -a outputfile.out

That will send the screen output both to the file outputfile.out and to the screen, which is nicer for checking progress along the way. :smile:

Those on Windows without Cygwin can probably get tee in [url=http://unxutils.sourceforge.net]UnxUtils[/url]; just place tee.exe in the same directory as ecm.exe (or somewhere on your path, if you prefer).

Another way to output both to a file and to the screen:
ecm -nn -c 10 26e7 < file.txt >> outputfile.out &; tail -f outputfile.out
or
echo "(3^607-1)/2" | ecm -nn -c 10 26e7 >> outputfile.out &; tail -f outputfile.out
(CTRL + C to end)

I'm running 10 curves, 1 done so far without finding a factor. I won't repost if these curves run to completion without yielding a factor, so as not to clutter the topic :smile:

P-1: B1=1e9, B2=1e14, no factor.

[QUOTE=Andi47;225814]
I will run a fistful of curves until my next GNFS (from aliquot sequence 10212) takes my ressources for a while.[/QUOTE]

cancelled / crashed, no single curve finished.

In a windoze environment it seems that it is [I]absolutely necessary[/I] to specify -maxmem 1800 (or smaller), even if you have [I]plenty[/I] of free memory and you are using Win 64 bit and a 64 bit ECM binary.

(ECM crashed when it tried to use more than ~1.8 GB (or 2 GB??) RAM, and I am pretty sure to have downloaded the 64 bit binary of ecm-6.2.3 (how can I check if this is indeed a 64 bit binary?))

[QUOTE=Andi47;225828](ECM crashed when it tried to use more than ~1.8 GB (or 2 GB??) RAM, and I am pretty sure to have downloaded the 64 bit binary of ecm-6.2.3 (how can I check if this is indeed a 64 bit binary?))[/QUOTE]

Run it (on something smaller so that it will run without crashing), and look in Task Manager. If it shows up as "ecm.exe *32" then it is 32-bit; if it is just "ecm.exe" then it is 64-bit.

[QUOTE=10metreh;225829]Run it (on something smaller so that it will run without crashing), and look in Task Manager. If it shows up as "ecm.exe *32" then it is 32-bit; if it is just "ecm.exe" then it is 64-bit.[/QUOTE]

Thanks. And oops, it seems that something went wrong when I downloaded the binary (maybe I copied it into the wrong directory), as it says that the binary I'm using is 32 bit.

Edit: Just downloaded the 64 bit binary and started a large p-1: it is running happily with a memory useage of 3.3 GB. :smile:

Anyone here wants to set up an ecmserver for this number?

[QUOTE=frmky;225800]NFS@Home is working its way up in difficulty toward a kilobit SNFS. We're at 285 digits now, and in about 1-2 months we will start a 290 digit number. sigma(3^606) = 3,607- is a very attractive number since it's simultaneously an OddPerfect roadblock, Cunningham 5th hole once the 3- extension is added (and 3,563- is finished, which will happen shortly), and a number with no known nontrivial factors. We would appreciate any help the OP community and others can provide. For now, the number needs more ECM. Currently a bit over 1*t55 has been completed, so it needs curves with B1 = 26e7.

The easiest way is to create a file containing the line

(3^607-1)/2

then run the command

ecm -c 10 26e7 < file.txt

Adjust 10 to the number of curves you wish to run. Just report the number of curves you have completed in this thread, and thanks in advance for any help you can provide![/QUOTE]

My personal opinion is that doing a number from the extensions, when
the extensions still have not been officially added to the table is
[b]ridiculous[/b]

There are many other suitable numbers, still undone, from the 1st printed
edition of the book. Let's work on finishing them.

[QUOTE=Andi47;225825]P-1: B1=1e9, B2=1e14, no factor.[/QUOTE]

extended B2 to 1e15, still no factor.