Welcome to the Leonids Shower Challenge

The Leonids is an average shower, producing up to 15 meteors per hour at its peak. This shower is unique in that it has a cyclonic peak about every 33 years where hundreds of meteors per hour can be seen. That last of these occurred in 2001. The Leonids is produced by dust grains left behind by comet Tempel-Tuttle, which was discovered in 1865. The shower runs annually from November 6-30. It peaks this year on the night of the 17th and morning of the 18th. The waxing gibbous moon will set shortly after midnight leaving fairly dark skies for what could be a good early morning show. Best viewing will be from a dark location after midnight. Meteors will radiate from the constellation Leo, but can appear anywhere in the sky.

Arithmetic progressions
In mathematics, an arithmetic progression (AP) or arithmetic sequence is a sequence of numbers such that the difference between the consecutive terms is constant. For instance, the sequence 5, 7, 9, 11, 13, 15 … is an arithmetic progression with common difference of 2.

An arithmetic progression of primes is a sequence of primes with a common difference between any two successive numbers in the sequence. For example 3, 7, 11 is an arithmetic progression of 3 primes with a common difference of 4.

For an arithmetic progression (AP) of primes, AP-k is k primes of the form p + d*n for some d (the common difference between the primes) and k consecutive values of n. The above AP-3 is 3 + 4*n for n=0,1,2.

How to Participate?
To participate in the Challenge, please select only the AP 27 (AP27) project in your PrimeGrid preferences section. The challenge will begin 17th November 2018 12:00 UTC and end 20th November 2018 12:00 UTC. Application builds are available for Linux , Windows and MacIntel CPUs and GPUs. CPU apps are only available for 64 bit CPUs. High end Nvidia GPUs will have a very large advantage.

Tasks will take ~29 hours on average for CPUs and ~75 minutes on average for GPUs. If your computer is highly overclocked, please consider "stress testing" it. If you haven't run the AP app before, we strongly suggest running it before the challenge while you are monitoring the temperatures. You don't want to turn your machine into a meteor!

Please, please, please make sure your machines are up to the task.

Time zone converter:

The World Clock - Time Zone Converter

NOTE: The countdown clock on the front page uses the host computer time. Therefore, if your computer time is off, so will the countdown clock. For precise timing, use the UTC Time in the data section to the left of the countdown clock.

Scoring Information

Scores will be kept for individuals and teams. Only tasks issued AFTER 17 November 2018 12:00 UTC and received BEFORE 20 November 2018 12:00 UTC will be considered for credit. We will be using the same scoring method as we currently use for BOINC credits.
A quorum of 2 is NOT needed to award Challenge score - i.e. no double checker. Therefore, each returned result will earn a Challenge score. Please note that if the result is eventually declared invalid, the score will be removed.

At the Conclusion of the Challenge

We kindly ask users "moving on" to ABORT their tasks instead of DETACHING, RESETTING, or PAUSING.

ABORTING tasks allows them to be recycled immediately; thus a much faster "clean up" to the end of a Challenge. DETACHING, RESETTING, and PAUSING tasks causes them to remain in limbo until they EXPIRE. Therefore, we must wait until tasks expire to send them out to be completed.

Please consider either completing what's in the queue or ABORTING them. Thank you. :)

For more information about the AP27 search, please visit these links:
- AP 27 Search
- AP 26 Search
- http://en.wikipedia.org/wiki/Arithmetic_progression
- Jens Kruse Andersen's Primes in Arithmetic Progression Records
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Tasks will take ~29 hours on average for CPUs and ~75 minutes on average for GPUs.

I never ran AP27 on CPUs. Anyone know if this application works well with multi-threading like LLR?

Good luck everyone!

There's a thread already on this but the short answer is I don't believe you can multi-thread AP's.

http://www.primegrid.com/forum_thread.php?id=8269

And if you are interested here's a thread on cpu times posted by a few folks who tested.

http://www.primegrid.com/forum_thread.php?id=8275

Where is my Post ?

I:m Suspend ?

What an auspicious start. It's a little early for the challenge, but we just found an AP26!

More details shortly. When I'm fully awake. After I hit the GO button on my crunchers when the challenge starts!

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My lucky number is 75898⁵²⁴²⁸⁸+1

After the first day:


Challenge: Leonids Shower
App: 11 (AP27)
(As of 2018-11-18 12:53:04 UTC)

72175 tasks have been sent out. [CPU/GPU/anonymous_platform: 8916 (12%) / 63259 (88%) / 0 (0%)]

Of those tasks that have been sent out:

4755 (7%) came back with some kind of an error. [337 (0%) / 4418 (6%) / 0 (0%)]
40281 (56%) have returned a successful result. [1584 (2%) / 38697 (54%) / 0 (0%)]
27142 (38%) are still in progress. [6995 (10%) / 20147 (28%) / 0 (0%)]

Of the tasks that have been returned successfully:

16088 (40%) are pending validation. [660 (2%) / 15428 (38%) / 0 (0%)]
24189 (60%) have been successfully validated. [924 (2%) / 23265 (58%) / 0 (0%)]
2 (0%) were invalid. [0 (0%) / 2 (0%) / 0 (0%)]
2 (0%) are inconclusive. [0 (0%) / 2 (0%) / 0 (0%)]
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My lucky number is 75898⁵²⁴²⁸⁸+1

Well, it appears that a good percentage of those errors were mine. Had a generally unmonitored host running PPS-Sieve for a long time so didn't notice that OpenCL got borked in a windows 10 update. Took a few driver reinstalls and reboots and it's back on track. Just wish I had checked it out sooner so as to not miss so much credit :(.
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Eating more cheese on Thursdays.

APs found so far during the challenge. To be in this list, the AP's finder had to return the task during the challenge, and it has to have also been validated by the double checker. The double check could happen after the challenge; what counts here is when the finder returned the task.

Between my own results and seeing it in the results you've posted, I've always been fascinated about the ~4:1 ratio of AP(n):AP(n+1) finds. Is there a known mathematical reason for this? I know there are an infinite number of APs, but I haven't come across any quantitative information in my searches.
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Eating more cheese on Thursdays.

One could try a semi-log plot and see if the points are on a line, and if the slope is consistent with that 1/4.0 hypothesis. /JeppeSN

Day 2L


Challenge: Leonids Shower
App: 11 (AP27)
(As of 2018-11-19 12:58:31 UTC)

126686 tasks have been sent out. [CPU/GPU/anonymous_platform: 14390 (11%) / 112296 (89%) / 0 (0%)]

Of those tasks that have been sent out:

8773 (7%) came back with some kind of an error. [766 (1%) / 8007 (6%) / 0 (0%)]
86966 (69%) have returned a successful result. [5480 (4%) / 81487 (64%) / 0 (0%)]
30948 (24%) are still in progress. [8144 (6%) / 22803 (18%) / 0 (0%)]

Of the tasks that have been returned successfully:

21984 (25%) are pending validation. [1388 (2%) / 20597 (24%) / 0 (0%)]
64977 (75%) have been successfully validated. [4092 (5%) / 60885 (70%) / 0 (0%)]
5 (0%) were invalid. [0 (0%) / 5 (0%) / 0 (0%)]
0 (0%) are inconclusive. [0 (0%) / 0 (0%) / 0 (0%)]
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My lucky number is 75898⁵²⁴²⁸⁸+1

With less than a day remaining in the challenge, it's time to remind everyone...

At the Conclusion of the Challenge

We would prefer users "moving on" to finish those tasks they have downloaded, if not then please ABORT the WU's (and then UPDATE the PrimeGrid project) instead of DETACHING, RESETTING, or PAUSING.

ABORTING WU's allows them to be recycled immediately; thus a much faster "clean up" to the end of a Challenge. DETACHING, RESETTING, and PAUSING WU's causes them to remain in limbo until they EXPIRE. Therefore, we must wait until WU's expire to send them out to be completed. Thank you!
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My lucky number is 75898⁵²⁴²⁸⁸+1

Hi Leonidists!

With significantly less than an hour to go for your work to qualify, are you biting your nails with a job that is predicted to end very close to the deadline?

Final totals:

Challenge: Leonids Shower
App: 11 (AP27)
(As of 2018-11-20 12:19:40 UTC)

172928 tasks have been sent out. [CPU/GPU/anonymous_platform: 17659 (10%) / 155269 (90%) / 0 (0%)]

Of those tasks that have been sent out:

12719 (7%) came back with some kind of an error. [1657 (1%) / 11062 (6%) / 0 (0%)]
133916 (77%) have returned a successful result. [10047 (6%) / 123869 (72%) / 0 (0%)]
25544 (15%) are still in progress. [5800 (3%) / 19744 (11%) / 0 (0%)]

Of the tasks that have been returned successfully:

20513 (15%) are pending validation. [1255 (1%) / 19258 (14%) / 0 (0%)]
113396 (85%) have been successfully validated. [8792 (7%) / 104604 (78%) / 0 (0%)]
7 (0%) were invalid. [0 (0%) / 7 (0%) / 0 (0%)]
0 (0%) are inconclusive. [0 (0%) / 0 (0%) / 0 (0%)]


Some totals on the APs found:

Well done dh1saj, you passed me out in the last few minutes :)

Good chase :)
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My lucky numbers 1059094^1048576+1 and 224584605939537911+81292139*23#*n for n=0..26

[H]atp1916 from TeAm AnandTech smashed it with 26,356,317 provisional points! More than total current credit showing on your AP badge, and AP24 discovered.
Street Creed to TeAm AnandTech with 86,625,318. Truly Beastful.

Better bring it to the next Challenge Brah

Remember to vote on next year's challenges: 2019 Challenge Voting

The cleanup begins! I expect the cleanup to take 3 to 6 weeks.

Leonids Cleanup:
Nov 20: Leonids Shower: 19854 tasks outstanding; 18650 affecting individual (296) scoring positions; 9307 affecting team (75) scoring positions.
Nov 21: Leonids Shower: 12899 tasks outstanding; 10631 affecting individual (287) scoring positions; 5614 affecting team (61) scoring positions.
Nov 22: Leonids Shower: 11024 tasks outstanding; 8846 affecting individual (280) scoring positions; 4817 affecting team (60) scoring positions.
Nov 23: Leonids Shower: 10593 tasks outstanding; 8510 affecting individual (278) scoring positions; 4638 affecting team (60) scoring positions.
Nov 24: Leonids Shower: 10265 tasks outstanding; 8141 affecting individual (275) scoring positions; 4502 affecting team (60) scoring positions.
Nov 25: Leonids Shower: 10015 tasks outstanding; 7893 affecting individual (272) scoring positions; 4402 affecting team (59) scoring positions.
Nov 26: Leonids Shower: 7133 tasks outstanding; 5041 affecting individual (247) scoring positions; 2191 affecting team (49) scoring positions.
Nov 27: Leonids Shower: 3549 tasks outstanding; 1843 affecting individual (181) scoring positions; 606 affecting team (33) scoring positions.
Nov 28: Leonids Shower: 1423 tasks outstanding; 500 affecting individual (116) scoring positions; 78 affecting team (15) scoring positions.
Nov 29: Leonids Shower: 699 tasks outstanding; 189 affecting individual (69) scoring positions; 8 affecting team (6) scoring positions.
Nov 30: Leonids Shower: 421 tasks outstanding; 100 affecting individual (47) scoring positions; 4 affecting team (3) scoring positions.
Dec 1: Leonids Shower: 261 tasks outstanding; 61 affecting individual (34) scoring positions; 3 affecting team (2) scoring positions.
Dec 2: Leonids Shower: 183 tasks outstanding; 50 affecting individual (30) scoring positions; 3 affecting team (2) scoring positions.
Dec 3: Leonids Shower: 168 tasks outstanding; 47 affecting individual (30) scoring positions; 3 affecting team (2) scoring positions.
Dec 4: Leonids Shower: 124 tasks outstanding; 37 affecting individual (22) scoring positions; 3 affecting team (2) scoring positions.
Dec 5: Leonids Shower: 73 tasks outstanding; 17 affecting individual (10) scoring positions; 0 affecting team (0) scoring positions.
Dec 6: Leonids Shower: 30 tasks outstanding; 3 affecting individual (2) scoring positions; 0 affecting team (0) scoring positions.
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My lucky number is 75898⁵²⁴²⁸⁸+1

The results are final!

Top 3 individuals:

1: [H]atp1916
2: vaughan
3: tng*

Top 3 teams:

1: TeAm AnandTech
2: Sicituradastra.
3: Czech National Team

Congratulations to the winners, and well done to everyone who participated.
See you at the Winter Solstice Challenge!
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I note that Tejas is no longer a member of Hagerhill KY. He joined The Scottish Boinc Team. Maybe the User stats don't get changed when you change teams after the fact, but Team stats do?
Users can also change teams during a Challenge, which creates all kinds of headaches for the scoreboards. As long as the treatment is consistent I don't think it matters a great deal.

Team scores are tabulated on a task by task basis. Each individual tasks contains a teamid as well as a userid. I'm fairly sure the teamid is set when the task is sent to a computer. If a user switches teams during the challenge, some of his tasks will be for different teams.

Worse yet, there's been cases where a team was deleted during a challenge. That actually broke the official challenge results once.

So, yeah, there's some strange stuff that can happen with the statistics.
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My lucky number is 75898⁵²⁴²⁸⁸+1