Links to Factoring Projects

[rogue]

Since we have a "Links to Factoring Programs" thread, I thought that it would be nice to have a list of factoring projects and their links. Here are a bunch; Paul Zimmerman has collected another bunch

Cunningham Project
NFSNet
Chez-Leyland which includes links to:

• Cunningham Numbers
• Homogeneous Cunningham Numbers (reservation page)
• Cullens and Woodalls
• Generalized Cullens and Woodalls
• Factorials + 1
• Factorials -1
• XYYXF Project

Eleven Smooth
Home Primes
World Integer Factorization Center which includes links to:

• Cyclotomic Numbers
• Repunits
• Repunits
• Near-, Quasi- Repdigit (M.Kamada)
• Partition Numbers
• Smarandache concatenated primes (eg 235711)
• Reverse Smarandache concatenated primes (eg 117532)

Another factorials +/- 1
Primorials +/- 1
Fibonacci and Lucas Numbers
Bernoulli and Euler Numbers

Euclid-Mullin Sequence

Maximal and minimal brilliant numbers

Smarandache numbers (eg 12345)
Reverse Smarandache numbers (eg 54321)

Sylvester's Sequence (explanation at wikipedia; this is a slightly impractical project since these are not SNFS numbers and no cofactor is less than 400 digits)

There is a result about base-2 pseudoprimes which would be assisted by factorisations of two annoying large numbers (a C183 and a C209, of impractical SNFS difficulty, so ECM's really all that will help, and they've been ECMed to at least t40), available here.

[henryzz]

it seems to me that the home primes project is inactive
is that so

[xilman]

Originally Posted by henryzz

it seems to me that the home primes project is inactive
is that so

I don't know. It may not be dead, it may only be sleeping.

There were times when Alex and I were the only people contributing and, because it could easily take us a month or more to complete a single factorization, it could easily appear to an onlooker that it was an ex-project.

Paul

[henryzz]

i havent looked that long but what evidence is there on the site that it hasnt been inactive since 2005
it says last updated then

[Shiva]

Originally Posted by henryzz

it seems to me that the home primes project is inactive
is that so

There seems to be more recent activity at:
http://www.mersennewiki.org/index.ph..._Primes_Search

[rogue]

Originally Posted by xilman

I don't know. It may not be dead, it may only be sleeping.

There were times when Alex and I were the only people contributing and, because it could easily take us a month or more to complete a single factorization, it could easily appear to an onlooker that it was an ex-project.

Paul

I've spent time on it, but not recently and not on HP49. It is a decent project for those who want to learn GNFS without taking on time consuming factorizations.

Would HP49 make an interesting candidate for NFSNet or is NFSNet only focused on the Cunningham project?

[sean]

Originally Posted by rogue

Would HP49 make an interesting candidate for NFSNet or is NFSNet only focused on the Cunningham project?

HP49 is currently 204 digits and thus exceeds the largest number ever factored with GNFS (at 200 digits). Also, the ECM effort is still only at the 110e6 level and thus may well still have factors below 60 digits. Before this number could be considered much more ECM would be needed, and even then I suspect there would be any number of better candidates near this size.

[bdodson]

Originally Posted by rogue

Since we have a "Links to Factoring Programs" thread,
...[*]Bernoulli and Euler Numbers
...

The above list of open numbers from Bernoulli, Euler and Bell is now
somwhat dated, as Sam has been using Purdue's condor grid, and also
asked me to have a look. Anyone considering a pass through these numbers
should check with Sam for a current list. As a particular instance, the
Euler number E196 = C328 = 5.29.197.C323 has a recent factor

p50 = 26034939865747697437451558982836040663625026070193

leaving a C274. If our local Gerbal regards this as too far off-topic
(and I'm not suggesting this as a place for regularly posting factors),
it might fit in the top10 thread over on gmp-ecm; the 2008 version
is now up to nine entries, with p51 and p53 Cunninghams pending
Paul's next update. -Bruce

[fivemack]

I have (ab?)used my Moderate Powers and created a thread for the Euler and Bernoulli numbers. If anyone wants to write and run the trivial perl script to parse out all the composite numbers into a text file suitable for ecmnet, I'll attach that file to the thread.

[rogue]

Originally Posted by fivemack

I have (ab?)used my Moderate Powers and created a thread for the Euler and Bernoulli numbers. If anyone wants to write and run the trivial perl script to parse out all the composite numbers into a text file suitable for ecmnet, I'll attach that file to the thread.

As long as you are at it, could you create a sticky for this thread, combine the links into the first post and delete any redundant/unneccessary posts?

Done evening of 11/1; the gerbil wishes to check that he has gnawed away all and only what should have been gnawed.

[jasong]

Could you add the Odd Perfect Number Search to the list?

I know it isn't an official project yet, but I'm sure if anybody wanted to throw a couple GHz weeks of power at it, wblipp would be happy to oblige them.

His ecm server isn't a dedicated server, so if the person is addicted to 100% cpu at all times, they'll want a backup ecm project in addition to attaching to his server.