Getting started
 

[B]The goal of the project is to factor x[SUP]y[/SUP]+y[SUP]x[/SUP][/B], known as Leyland numbers, for 1 < y < x < 151.

There's a pretty outdated homepage with a short description: [url]http://www.primefan.ru/xyyxf/default.html#0[/url]
The project has a 13-year history, so there are some milestones: [url]http://www.primefan.ru/xyyxf/news.html#0[/url]
All the composites up to x = 100 inclusively had been factored: [url]http://www.primefan.ru/xyyxf/results.txt[/url]
The list of factorizations for 100 < x < 151 is given there: [url]http://www.primefan.ru/xyyxf/results2.txt[/url]
The most recent results: [url]http://www.primefan.ru/xyyxf/results.html#0[/url]
The most interesting results: [url]http://www.primefan.ru/xyyxf/records.html#0[/url]
The detailed list of contributors: [url]http://www.primefan.ru/xyyxf/contributors.html#0[/url]
The full list of composites: [url]http://www.primefan.ru/xyyxf/cmplist.txt[/url]

The composites are named Cddd_xxx_yyy, where ddd is the decimal length, xxx is the decimal value of x, yyy is the decimal value of y (may have only two digits).

[B]Currently all the composites are ECM or NFS targets.[/B]
The detailed status is reported there: [url]http://www.primefan.ru/xyyxf/status.html#0[/url]

ECM tests with B1=110M are being performed by [url=http://www.rechenkraft.net/yoyo/]yoyo@home[/url]: [url]http://www.rechenkraft.net/yoyo/download/download/stats/ecm/xy/wu_status[/url]
Some deeper ECM tests were performed on particular composites: [url]http://www.primefan.ru/xyyxf/status.html#work[/url]
So far, most of the composites need more ECM work to become feasible NFS targets. Those which has been survived enough ECM tests are collected there:
[url]http://www.mersenneforum.org/showthread.php?t=19352[/url]
[url]http://www.mersenneforum.org/showthread.php?t=19353[/url]

[B]The best way to contribute[/B]
is either to run some ECM tests: [url]http://www.mersenneforum.org/showthread.php?t=19369[/url]
or to perform a full SNFS or GNFS factorization: [url]http://www.mersenneforum.org/showthread.php?t=19368[/url]

There are also some detailed (but also outdated) instructions how to make a contribuiton:
Overall strategy: [url]http://www.primefan.ru/xyyxf/how.html#0[/url]
Reservations: [url]http://www.primefan.ru/xyyxf/reserve.html#0[/url]
Various links: [url]http://www.primefan.ru/xyyxf/links.html#0[/url]

When will you update the webpage with last two months results?

Thank you

Carlos

That's what I'm doing right now :)

The pages were updated again: [url]http://www.primefan.ru/xyyxf/status.html#0[/url]

Join?
 

I sent an email to xyyxf AT mail.by but Microsoft says there is no such account. Below are its contents.

May I join the XYYXF project? Or is it down now?
I’m Daniel Lu, and my email is dlc0424 AT outlook.com. I’d like to have my username, if possible, as dannyridel. I run JonDan School Services with my friend Jonathan at jondan-school-survices.business.site. I really love these primes and composites and have joined multiple other projects including PrimeGrid, CRUS, GIMPS, and YAFU and NFS. I learned about XYYXF through mersenneforum.org. I have bad network here in China so I really need some help starting to factor by myself without access to the files that are on the website. Thank you!

Hello Daniel. Unfortunately the XYYXF project leader Andrey seems to have withdrawn from the project. However work on the project continues. I and others have been slowly factoring the XYYXF composites with 1 < y < x < 151. Some updates are [url=https://www.mersenneforum.org/showthread.php?t=22530]here[/url].

Users pxp and NorbSchneider are busy finding/indexing Leyland primes. They both provide [url=https://www.mersenneforum.org/showthread.php?t=19347&page=30]frequent updates[/url].

Andrey was the only person to have control of the xyyxf page so no updates of it are possible. But there was never any “joining” the project - just start working on something that interests you but be sure to post your intent here. But please try to avoid colliding with the work of others.

[url= https://www.rechenkraft.net/yoyo/y_status_ecm.php]Yoyo@Home[/url], a math project utilizing the BOINC wrapper, has been running ECM on each remaining XYYXF composite. Almost all remaining composites have survived 18000 curves with B1=110e6, also called t55 (tested to the 55-digit level). Yoyo should have every composite tested to the t55 level by June 2020.

Post any questions you may have.

Sean

As of now I'm going to settle with Yoyo@Home, which coincidentally I joined last week. Thank you for your reply and best wishes for Andrey.

Is anyone interested in resurrecting this project?

I'm not suggesting that I will do that work, just asking if anyone else wants to.

The other x^y+y^x search is by bit length and not by x. Although maybe pxp or NorbSchneider would like to put up a page for prime hunters who want to search by x.

[QUOTE=rogue;550480]Is anyone interested in resurrecting this project?

I'm not suggesting that I will do that work, just asking if anyone else wants to.

The other x^y+y^x search is by bit length and not by x. Although maybe pxp or NorbSchneider would like to put up a page for prime hunters who want to search by x.[/QUOTE]I may be. I contributed in the past but the GCW project has taken up much of my resources recently.

If you want to take over the project web page ...

[QUOTE=xilman;550483]I may be. I contributed in the past but the GCW project has taken up much of my resources recently.

If you want to take over the project web page ...[/QUOTE]

I'm thinking it could be split into two different projects, one for prime hunting and one for factoring.

I’ve been here the whole time, working on xyyxf factorizations. Mostly wrangling the remaining composites through Yoyo@Home. Ryan Propper occasionally factors a larger job, though not for awhile.

A few xyyxf composites have completed ECM to the t60 level and are ready for NFS, if anyone is interested.

Only Andrey had the keys to the project site, and he’s not been heard from since 2017. I heard he got married and stepped back from xyyxf factoring. How dare he! :smile:

I pinged him today and he wrote back!
He is actually alive and well! (But I only know this much.)