Team sieve #24: c155 from 4788:2618
 

After another exciting round of Find The Factors, we now come to a c155 on the very next line after a c172 (so easier, but still not a walk in the park).

[B]22 Feb 2011: Post-processing has begun!
24 Feb 2011: Post-processing complete! c155=p72*p84. Next up is a [URL="http://factordb.com/index.php?id=1100000000295928243"]c152[/URL] that bchaffin has started sieving.[/B]

The poly:[code]n: 75932340428877011727618708726905558562515248304152927449065726063130564403655850880406162753916607273084882142223225126840338325892660195804478997023817401
# norm 4.025205e-15 alpha -7.671371 e 2.488e-12 rroots 3
skew: 42373826.68
c0: -58398068784506051024477192866875977892800
c1: -167100295795302960137099458278320
c2: 511004049252803790191305716
c3: -13968245979099022648
c4: -357816499243
c5: 996
Y0: -2379225273126981752554350978483
Y1: 158202809821186829
rlim: 25000000
alim: 25000000
lpbr: 29
lpba: 29
mfbr: 58
mfba: 58
rlambda: 2.5
alambda: 2.5[/code]Sieve special_q on -a side from 20M to 64M using siever 14e.

Post-processing will be done by bchaffin.

Sieve reservations:[code]20-40 bchaffin
40-42 jrk
42-50 bchaffin
50-60 bchaffin
[/code]

[QUOTE=jrk;253081]Alright good, so round that up to the next region and the specialq range is 20M to 64M.

Sieving can begin whenever![/QUOTE]

I started about 10 minutes ago. :smile:

I can do the post-processing for this one. Alone, the sieving will take me about 3 days or a little more, so I'm OK to do it on my own. If others want to sieve as well and upload to sendspace, we can have the answer sooner. For now I'll work on 20M-40M.

[QUOTE=jrk;253078]Use the params from [url=http://www.mersenneforum.org/showpost.php?p=253019&postcount=1111]this post[/url], and if you don't mind doing a little more work, sieve samples of specialq's in ranges of 1000 for each 2M, starting at 20M, and see how far you have to go to get about 28500 relations. The upside of doing this is so that we get a nice range to work in, without having to worry about going overboard with the sieving and making the filtering/LA harder.[/QUOTE]

May I ask where the 28500 came from and/or was calculated?

RichD.

[QUOTE=RichD;253084]May I ask where the 28500 came from and/or was calculated?

RichD.[/QUOTE]
From past experience, we want about 57M raw relations (before discarding dups) for a task this size using these parameters. Testing 1/2000 of the specialq's (a test range of 1000 for each 2M range) would yield about 28500 relations (1/2000 of 57M) from the sample ranges over which we'll need to sieve.

[QUOTE=bchaffin;253083]For now I'll work on 20M-40M.[/QUOTE]
I'll start 40M-42M. ETA two days.

[QUOTE=jrk;253086]From past experience, we want about 57M raw relations (before discarding dups) for a task this size using these parameters. Testing 1/2000 of the specialq's (a test range of 1000 for each 2M range) would yield about 28500 relations (1/2000 of 57M) from the sample ranges over which we'll need to sieve.[/QUOTE]

So 57M is based (only) upon the size, c155??

Thank you for the reply. I'm still working my way through SIQS and such, but looking ahead into GNFS.

RichD.

I went ahead and changed the ECM thread to an NFS thread; hope that was OK.

100 ECM curves at B1=11e7, no factor. (these have been running overnight.)

60@850M, no factor (these have been running overnight)

Are there some more ECM curves needed, I can run them in yoyo@home?

Which is the number to factor and which are the curves required for different B1 values?

yoyo

[QUOTE=yoyo;253116]Are there some more ECM curves needed, I can run them in yoyo@home?

Which is the number to factor and which are the curves required for different B1 values?

yoyo[/QUOTE]

Thanks for your offer to help, but for this one we have already done a few more curves than needed. Sieving has started this morning, and if I see correctly, ETA seems to be ~3-4 days.

I am sure the next composite which needs some ECM will be here soon.