staff blogs staff keep (relatively) up-to-date logs of their activities in .plan files. These were traditionally available via finger, but we've put them on the web for easier consumption.


Completion of OGR-28 project

Filed under: project status @ 03:28 +00:00

Dear friends, is proud to announce the completion of OGR-28 after approximately 8.5 years, with the help from our network of volunteers!

We started our calculations to prove the optimal Golomb ruler with 28 marks in February 2014 just a few days after we proved the optimal one with 27 marks.

While we are a little disappointed that we were not able to find a more optimal one than the previously predicted one, we have proven conclusively using an exhaustive search that it is indeed optimal. That previously known ruler has the following marks: 0 3 15 41 66 95 97 106 142 152 220 221 225 242 295 330 338 354 382 388 402 415 486 504 523 546 553 585

or it can be written in our alternative notation: 28/3-12-26-25-29-2-9-36-10-68-1-4-17-53-35-8-16-28-6-14-13-71-18-19-23-7-32

That known solution was discovered twice by our volunteers. The first time was in March 2015 and then more recently in July 2022. We will be contacting those two people and sending them some nice gifts.

More than 65,000 volunteers from more than 80 countries around the world contributed to this success. We verified 524,091,443 stubs (yes, even the 4 which show on the Stubspace Status page as incomplete) while requiring each to have been completed at least two times independently and with an identical node count.

We don’t have plans to work on OGR-29 at the moment, due to its currently projected size and duration, but we will continue to keep it in mind for the future.

Our RC5-72 project remains very much alive and well. Should you be interested in continuing to help our endeavors, feel free to adjust your clients to work on that project. For many of you, the nostalgia factor of RC5-72 may bring a nice smile to your face! (It’s also quite fun to see how your 2022 hardware fares, compared to your keyrates of old).

We are grateful for all of your contributions. Moo! ]:8)