12121 Search

Searching since 5/24/2004 for large primes of the form 121*2^n-1

12121 Sister project #1, 2721, has been made open to the public for testing. Help out here!

12121 search is pleased to announce their partnership with PrimeGrid. PrimeGrid has been running a number of projects, including 321 search and Prime Sierpinski Problem through the BOINC client. Starting at n=3.7M for k=121 and n=1.85M for k=27, PrimeGrid will be coordinating all reservations. The 12121 project will still be in existance, and this will be its website for team updates. Please join PrimeGrid and then join team 12121 search to stay active with the project. We will also be adding +1 for both k=27 and 121. Additionally, you are now able to make reservations and assist with sieving. Reservations will now be fully automatic through PRPnet and soon the BOINC client.

Top Ranking 12121Search participants

Our Top Primes

Most recent: 1/28/2006 - 121*2^2033941-1 found by Simon. It has 612,280 digits and is ranked 22 on the all time list. Great work Simon! Apparently he took that last "Keep up the good work" very seriously. Good luck on the next one Simon!

Recent: 1/21/2006 - 121*2^1954243-1 found by Simon. It has 588,288 digits and is ranked 24 on the all time list. Great work Simon! Keep up the good work.

Interested in helping?

Status of the project:

-Completed sieve up to n=10,000,000 (Current sieve depth: 290T)
-Completed search up to 3,450,000
-Completed ranges appear in green, reserved ranges in blue, and available ranges in orange

Interested in helping out with this project but don't know where to begin? Check out the Quick Start guide

Reserve a Range
If this is your first range, please email vanklein [at] gmail [dot] com so that I have your contact information in case there is a problem with your range. If you don't, your range will be released within one week of reserving it

Submit Results

Project contributors include or have included: Justin Van Klein, Ryan Jackson, Rodger Ewing, Daniel Medici, JF Boyer, Nick Thornton, Cedric Vonck, Michael Haas, Ed Dillo, Frank Clowes, Veejay Maharaj, James Burt, George Koos-Hutas, Chris Chatfield, Janne Suikkala, Tommy Nolan, Mike Binns, Clare Elliot, William W. Mikrut, Chris Peace, Ken Linder, Dhumil Zaveri, Tony Galvan, Marco Reschke, Raphael Hogger, Thomas Bunk, Szymon Banka, Christian Klimbache, Ville Vainio, David Harrison

So you've found a prime? Heres how to submit it to the top5000 database.

1. go to http://primes.utm.edu/bios/newprover.php
2. Put in your full name, username (last name) and an email address
3. Go to your biographical page when you get your email. (there should be a link once you get an email from the, but if its not, you can find it here http://primes.utm.edu/bios/page.php?id=xxx where xxx is your id number that they email you)
4. Click create a new proof code.
5. Under proof method select Jean Penne's LLR
6. In the box below where it says "none" erase that and type in "12121search, sr1sieve" without the quotes
7. Click submit.
8. Make sure all of the information is correct and then press to complete submission at the bottom
9. Click on your last name (or username) on the next page
10. At the bottom it will say "Submit primes using the code: ___" (click on the new code.)
11. In the box type in your prime (121*2^xxxxxxx-1, where 121 is the base and xxxxxxx is the exponent of your found prime)
12. Submit it, and you'll be all set