Reserved for MF - Sequence 3366

[RichD]

I will start sieving soon. Poly almost done.

[EdH]

Found probable prime factor of 44 digits: 39580242975757113790733052958481530034022517

next one (c172) looks intimidating...

[RichD]

Yay! Didn't have to sieve it.

A p44, that should have been picked up by yafu because a full t45 would be in order. :/

[RichD]

2^3 * 3^2 * 233 * c172

-pm1 5e9 - nothing

[RichD]

660 @ 11e6 - nothing
520 @ 43e6 - nothing

Pausing to run a NFS@H job.

[EdH]

3860@11e6
2000@43e6
600@11e7

[RichD]

Passing through

220 @ 11e7

This will be slow going. I'm afraid we may end up with two sequences sitting at a C172.

[EdH]

Originally Posted by RichD

Passing through

220 @ 11e7

This will be slow going. I'm afraid we may end up with two sequences sitting at a C172.

Afraid I have to agree. I'm up over 1200@11e7 (total so far). The 4788 c173 has had a "lot" more ecm done on it, though. But, I'll probably shift over to 3408 for a bit. I don't think my attention span can endure the gnfsing of a c17x. What memory requirements would there be for a c172/c173?

I suppose there are a couple things to consider:

1. The c173 has had a lot of ecm, the latest being 70005@85e7. That means we're closer to finding a record ecm factor for it, but it also means we'd probably need a lot more curves to find it. That number is probably past being ready for gnfs.

2. Truly, I suppose we've only brushed the tip of the c172 with ecm, and shouldn't be looking toward any team sieve for it any time soon.

I suppose that leaves working with 3408 for a while...

[RichD]

Totally agree.

1. 4788 c173 is definitely ready for GNFS. I'm not sure the enthusiasm given the low interest level of these two "relatively" new sequences.

2. We have acres to go into 26e7 before considering GNFS. Hopefully, some factor searching ECMer may come across a nice find.

Seq 3408 may be the main focus for the immediate future with some ECM curves on 3366 here or there.

BTW, these GNFS projects will require the 15e siever. This is beyond a request to NFS@Home because they have so many in backlog to meet other obligations.

[VBCurtis]

Does 15e require 1GB per thread to sieve?
I wish one of these were in the high 160s, as I'd like to participate in a big-ish factorization; but 170+ is pretty serious given the interest shown so far.

Isn't one of the problems with 4788 interest its driver? I mean, if we do the c173 there's no reason to think we'd go long before another serious roadblock?

[schickel]

For comparison, I did a c168 at the beginning of the year (running from March thru May).

Originally Posted by VBCurtis

Does 15e require 1GB per thread to sieve?

I'm not sure about the memory use, but I think it did seem to run around that range--maybe 10% higher, but then my sieve machines both have 8GB, so the sievers didn't get in the way.

I wish one of these were in the high 160s, as I'd like to participate in a big-ish factorization; but 170+ is pretty serious given the interest shown so far.

Hmmm, well, it's not high-160s, but I have a c163 in my queue that I want to tackle sometime this year. Let me know if you'd be interested.

Isn't one of the problems with 4788 interest its driver? I mean, if we do the c173 there's no reason to think we'd go long before another serious roadblock?

Unfortunately, yes, the driver is the big issue, especially since the most of the last 20 lines have had a factor of 3 thrown in for good measure. The primary driver (as it were) for me would be the chance to push the sequence to 180 digits or higher.....but I figure that 7044 is going to be a little easier to do that with than 4788.