GNFS targets which need more ECM

[wombatman]

Woo! I'll definitely still be around--just working on some things in the mean time.

[VBCurtis]

I'll be ready to go Monday on GPU at 3e8. Please post/link the first number you'd like to tackle.

I've been reserving my GPU for my biggest SNFS projects, since ecm runtime is independent of input size on GPU, but ~linearly correlated on CPU. Since the GPU is relatively less useful on these GNFS candidates, I'll limit my contribution to 1600 stage 1 curves per candidate, minimum 181 digits.

swellman- the demo residues I sent you were C261; the ~C18x's we'll cooperate on here should take about 70% of the stage 2 time that your demo ran.

[fivemack]

C187_142_59 might be a nice one to start with.

[swellman]

C187_142_59 is good. The curve count in the
OP table is 12k @B1=3e8 but I'll take whatever number of curves you choose to run. Thanks.

[VBCurtis]

I haven't followed this project very closely; where do I find the actual composite?

[pinhodecarlos]

Originally Posted by VBCurtis

I haven't followed this project very closely; where do I find the actual composite?

Here Curtis: http://www.primefan.ru/xyyxf/cmplist.txt

[swellman]

All xyyxf composites can also be found in factordb.

[swellman]

Originally Posted by swellman

I am continuing with the factorization of the remaining composite cofactor.

prp54 = 900824071012862154326311230178799166176399213719911023
prp81 = 109243157581182881020126105012047635554735414913089609634355144511689971747832823

Found using GNFS on my own hardware.

[swellman]

Originally Posted by swellman

C179_148_87 is a composite cofactor (stub) from a yoyo ECM effort on C223_148_87. See http://factordb.com/index.php?id=1000000000044706172.

After ECM to t55, it should be a straightforward GNFS.

Ben - shall we enqueue this number for our Stage 1-2 process?

After Wombatman ran Stage 1 on this number, we got a hit in Stage 2:

Using B1=110000000-110000000, B2=776278396540, polynomial Dickson(30), sigma=3:4168111304
Step 1 took 0ms
Step 2 took 260194ms
********** Factor found in step 2: 790095244293711487005528692675112474163842042179282725999
Found prime factor of 57 digits: 790095244293711487005528692675112474163842042179282725999
Prime cofactor ((87^148+148^87)/1157316370657702985095391424238064814231555506492832039737575734950799505448628991056787083247178604795448487)/790095244293711487005528692675112474163842042179282725999 has 123 digits

[swellman]

Originally Posted by wombatman

I can go ahead and do that one. I just finished the previous one.

Reserving C184_149_81 for 18k curves at B1=110e6.

Another factorization by ECM!

Using B1=110000000-110000000, B2=776278396540, polynomial Dickson(30), sigma=3:295950835
Step 1 took 0ms
Step 2 took 379441ms
Factor found in step 2: 19113407407889063365267135735711533345980263098061
Found prime factor of 50 digits: 19113407407889063365267135735711533345980263098061
Prime cofactor 370153936843325115653510049830849323689182005751811819885480216171979046194004537354783253144418701459451015115346252515931341058386539 has 135 digits

[wombatman]

Wow!