3,599+ status and discussion

[akruppa]

Originally Posted by R.D. Silverman

What's the status of 3,499+?

Alex:

Did you get the data that I sent by snail mail?

Bob

Yes, received it, thanks! Between your set and mine, there are currently 24095194 unique relations here.

Edit: actually, it's 25123591 unique relations now. I just transferred a new batch of files from the TU München.

Btw, Paul: Please remind me which interval you are sieving. I'd like to avoid duplication.

Alex

[akruppa]

Current count on my end is 27543834 unique relations.

Edit: sorry, it's 30155284. I had a parameter (-lp) wrong during the filtering.

Update (2007.04.10) : 33240022 unique relations.
Update (2007.04.16) : 36526558 unique relations.
Update (2007.04.26) : 40192316 unique relations.
Update (2007.05.15) : 48477140 unique relations.
Update (2007.05.29) : 52116454 unique relations.
Update (2007.07.02) : 59803271 unique relations.
Update (2007.07.20) : 64934927 unique relations.

Alex

[akruppa]

The matrix job is now running, estimated time to completion is 36 days at the moment. It is very early in the run, though, so that figure may change.

Alex

[xilman]

Originally Posted by akruppa

The matrix job is now running, estimated time to completion is 36 days at the moment. It is very early in the run, though, so that figure may change.

Alex

How big and dense is the matrix?

Paul

[akruppa]

It's "6889926 x 6893757, total weight 620937048." It probably is a bit too heavy, but I had some problems building the matrix (mostly due to poor planning on my part) and don't have the time/patience to start over. So I took the first matrix of valid dimension I got and ran with it...

Alex

Update (18.9.2007): The matrix is 50% done now.
Update (18.10.2007): Block-Lanczos on the matrix is paused at the moment as the machine is used for other work at the moment. It is 77% done and will take a bit over a week to finish once I resume computation.

[akruppa]

Probable prime factor 1 has 113 digits:
50291482856324544404027093373360635121063081581216864654202148086500144195079163724148106275521673861082817129401
Probable prime factor 2 has 125 digits:
60249253834468029722846922340566907742203320456026527837840758742969239944910379299755028256308064416617431085523496168044367

Sqrt was a bit of a pain because we used an lp bound of 2^30 with Franke's lattice siever and I forgot to remove relations with primes >10^9, which CWI's sqrt uses as CRT primes. I found a long enough interval of primes that don't appear among the relations and let sqrt use those, the rest went pretty smoothly.

The p113 replaces my p108 of 5,349- as the second largest penultimate factor found within the Cunningham project.

Alex

[fivemack]

Congratulations! That's a spectacular factorisation, after an enormous amount of work.

How many relations did you end up using, and have you got an estimate for the sieving effort in CPU-hours?

[bdodson]

Originally Posted by akruppa

Probable prime factor 1 has 113 digits: ...
Probable prime factor 2 has 125 digits: ...

The p113 replaces my p108 of 5,349- as the second largest penultimate factor found within the Cunningham project.

Alex

Congratulations, indeed; especially great to see how to fix
the crt overlap. I'm looking forward to more of these large
numbers. Any thoughts on either of

> 3,508+ C188 (difficulty 242.38) or 3,512+ C193 (diff 244.29)
> from the more wanted list?

With greg's sieving contributions these are near nfsnet range,
but not for a while yet; not sure whether joint or separate projects
would be better. Some other next-next candidates would include

> MWN-#9, 12, 227+ C213, at difficulty 244.97 ... then a huge number at
> 12, 229- C242, the largest cofactor on the wanted lists, at difficulty 247;
> I'd like to see all four factored. [and] there's 10,239+ (diff 239).

I'd try to finish testing to p55 if/when there's confirmation that they're
near-term sieving candidates. -Bruce

[R.D. Silverman]

Originally Posted by bdodson

Congratulations, indeed; especially great to see how to fix
the crt overlap. I'm looking forward to more of these large
numbers. Any thoughts on either of

> 3,508+ C188 (difficulty 242.38) or 3,512+ C193 (diff 244.29)
> from the more wanted list?

With greg's sieving contributions these are near nfsnet range,
but not for a while yet; not sure whether joint or separate projects
would be better. Some other next-next candidates would include

> MWN-#9, 12, 227+ C213, at difficulty 244.97 ... then a huge number at
> 12, 229- C242, the largest cofactor on the wanted lists, at difficulty 247;
> I'd like to see all four factored. [and] there's 10,239+ (diff 239).

I'd try to finish testing to p55 if/when there's confirmation that they're
near-term sieving candidates. -Bruce

CWI is doing 12,229-.

[bdodson]

Originally Posted by R.D. Silverman

CWI is doing 12,229-.

Yes; I ought to have recalled that, thanks! The other two
I was thinking of, once 2,787-/+ are nearer clearing were

M821 = 2,821- C208 (which will be a new 1st hole after we
finish 787-), at difficulty 247; and, a bit further out yet,
there's M841 = 2, 841- C245, at difficulty 253. -Bruce

[akruppa]

Originally Posted by fivemack

Congratulations! That's a spectacular factorisation, after an enormous amount of work.

How many relations did you end up using, and have you got an estimate for the sieving effort in CPU-hours?

There were 75784708 unique non-free relations overall. After singleton removal (examining ideals of norm >1M), 37510063 non-free relations remained on 36816190 ideals, excess 2339180. I reduced excess to 350k and merged to get the matrix dimension listed above.

I didn't keep track of the cpu time I spent sieving, and Bob and Paul contributed a lot of relations. Sorry, I have no good estimate of how much cpu time we spent.

Alex