Factoring humongous Cunningham numbers

[Yamato]

Originally Posted by xilman

Wow!

Have you told the other Paul about this one?

Yes. This p67 means rank 24 in the top50 list http://www.loria.fr/~zimmerma/records/top50.html.

[bdodson]

Originally Posted by Yamato

Yes. This p67 means rank 24 in the top50 list http://www.loria.fr/~zimmerma/records/top50.html.

It also will be in 7th spot on the current Top10 for 2013, following
six R. Propper factors. In 10th spot is a p65, which is ALREADY
(in May!) the largest factor ever in the 10th spot among the annual
Top10s. So that's p67-Y, p67-W, p66-alsoW,re_found-D and p65-RP.
Since this is only May, we might imagine one-or-more of the p67's
being bumped; a large bump in ecm performance as measured by
the 10th number at the end of the annual Top10.

In particular, people factoring using sieving methods will be tempted
to refer to found p67's as "ecm misses", with the 10th-on-the-Top10
as evidence for finding p67's being routine. Leaving us ECM partisans
to mutter about whether there was a 2p65 test run, to give ECM a
fair chance. But still, how hard could it have been to find the 10th
largest ecm factor of the year? Guess that's a 2t65 standard. Hard
to meet with just a few 100 cores.

-Bruce (cf. "few 1000 cores")

[R.D. Silverman]

Originally Posted by bdodson

It also will be in 7th spot on the current Top10 for 2013, following
six R. Propper factors. In 10th spot is a p65, which is ALREADY
(in May!) the largest factor ever in the 10th spot among the annual
Top10s. So that's p67-Y, p67-W, p66-alsoW,re_found-D and p65-RP.
Since this is only May, we might imagine one-or-more of the p67's
being bumped; a large bump in ecm performance as measured by
the 10th number at the end of the annual Top10.

In particular, people factoring using sieving methods will be tempted
to refer to found p67's as "ecm misses", with the 10th-on-the-Top10
as evidence for finding p67's being routine. Leaving us ECM partisans
to mutter about whether there was a 2p65 test run, to give ECM a
fair chance. But still, how hard could it have been to find the 10th
largest ecm factor of the year? Guess that's a 2t65 standard. Hard
to meet with just a few 100 cores.

-Bruce (cf. "few 1000 cores")

Might a table update be in order?

[xilman]

Originally Posted by R.D. Silverman

Might a table update be in order?

You're quite right. Mea culpa.

Paul

[xilman]

Originally Posted by R.D. Silverman

Might a table update be in order?

Here is the long-delayed listing of (relatively) recently found factors.

5+3	343	C180	214277969355591676991097476299105965108022283299646501141963321729558444840198321611097.	P94		J Becker		SNFS	2013-03-04
9+5	233	C205	136367117423127860254895236408139546024350907030849.	C155							R Silverman		ECM	2013-03-04
4+3	377	C156	26577128521470478405994117612046765835228524644810222158206934835787884089.	P83				J Becker		SNFS	2013-03-06
5+3	335	C148	22925829560874450829460335931147224802521809315474144240304015927989641071.	P74				R Smith			GNFS	2013-03-08
7-4	239	C148	13439954871716634615006953783420002473245231871430106670826518219060487.	P78				R Smith			SNFS	2013-03-18
9-2	233	C208	144449636439492792079289990466593043176096349193.	P161							R Silverman		ECM	2013-04-05
5+4	353	C210	57794688287965904955333745036443245606178007189.	C163							R Silverman		ECM	2013-04-15
11+7	212	C148	215176474166427763984632576591525186707321639165169433589297689.	P86					R Smith			GNFS	2013-04-20
11+8	226	C162	3131017808221386938986002456551192811297622868985354075728273561.	P98					A Edwards		GNFS	2013-04-22
7+6	275	C166	11981754656485778090729532208816604624847202279601.	P117							S Wellman		SNFS	2013-04-29
10+9	236	C168	2970502746365749876818923808989713022319848931047956587856682374457.	P102					K Schönberger		ECM	2013-05-03
5+3	322	C158	28997963732894660095321909269889802465659885697667979122805641874601429.	P87				J Becker		SNFS	2013-05-07

Thirteen factors have been found in the last couple of months and there are now 465 composites remaining in the tables.

The corresponding data will be uploaded to the web shortly, assuming my ISP's ftp service is running. It's been a bit flaky recently.

Paul

[jyb]

There are still two missing numbers:
7-5,265
9+5,247

The first of these shows up in the FactorDB, so I guess we can let this be a report (I'll send it to Paul via email as well):

7-5,265 C136 = P59*P77
P59 = 58533493203446119589396782586974563479438080167874214853541
P77 = 23625734841866042894923325637805186189583124299664196997518267066535394484901

Tom, can you look up the factors for 9+5,247 in your reservation page logs?

[bdodson]

Originally Posted by Yamato

Yes. This p67 means rank 24 in the top50 list http://www.loria.fr/~zimmerma/records/top50.html.

The other Paul seems not to have recorded this p67; which should be
in both the top50 (all time; all ecm) and the top10 for 2013. Any chance
someone here might remind him? I'd do so myself with an ECMNET
report, but our condor server for the pc-grid is down for new hardware;
may be a while before my next ecm factor. -Bruce

[fivemack]

Originally Posted by jyb

Tom, can you look up the factors for 9+5,247 in your reservation page logs?

bsquared reported the factor 2561578747468682452959364472506747672788903875691385944952129063 for this number on 24 January 2013.

[pinhodecarlos]

207.192.74.48:8194 server is down. Paul, can you contact Justin Card? Thank you in advance. Carlos

[jyb]

Originally Posted by pinhodecarlos

207.192.74.48:8194 server is down. Paul, can you contact Justin Card? Thank you in advance. Carlos

It's down now as well. Is that again, or still?

[pinhodecarlos]

Still down since 30 May.