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-   -   Sequence terminations and merges (https://www.mersenneforum.org/showthread.php?t=11837)

 Andi47 2009-09-11 15:12

[QUOTE=10metreh;189474]I've listed it as a termination - I think it should only be a merge if the sequence that it merges into is open.

But this would cause problems if someone found a merge, countinued working on the merged sequence, and terminated it...

...but luckily we haven't had that happen yet.[/QUOTE]

Then it would only be a "merge" as long as it is not terminated.

 10metreh 2009-09-11 15:17

[QUOTE=Andi47;189484]Then it would only be a "merge" as long as it is not terminated.[/QUOTE]

Right, this is getting a bit confusing. If the scenario I mentioned does happen, then I will get REALLY confused. Therefore all we need to do to get me really confused is to [spoiler]get biwema to work on all the sequences mentioned in the last column of the table in the first post. (i.e. 126792, 660, 102936 etc.)[/spoiler] :wink:

 Greebley 2009-09-11 17:07

If a sequence can go from open ended to prime, then I think one could go from merge to prime as well.

I think the ultimate find would be a sequence that merges with itself. If so you have found a cycle that is hundreds or thousands long and beat the mere 28 that is the record now.

 10metreh 2009-09-11 17:09

[QUOTE=Greebley;189497]I think the ultimate find would be a sequence that merges with itself. If so you have found a cycle that is hundreds or thousands long and beat the mere 28 that is the record now.[/QUOTE]

My bet with myself is that a cycle at least 1000 iterations long will be found by the end of 2012.

(The chances are higher than you might expect - about 1/6 of the numbers below 1000000 do not terminate in a prime, but are either open or merged. So 276 does not just have to drop down to 276 to merge - it could drop to 306, 396 or any other number that merges with it and still a really long cycle would be formed.)

 smh 2009-09-14 19:50

I forgot to report this.

914850 terminates

Thanks to kar_bon for notifying mee.

 unconnected 2009-09-15 19:29

[URL="http://factordb.com/search.php?se=1&aq=546120&action=last20&fr=&to="]546120[/URL] merges at i=1645 with 334034

 Greebley 2009-09-15 23:54

I got another termination after reaching 115 digits at index [URL="http://factorization.ath.cx/search.php?se=1&aq=507924&action=range&fr=678&to=691"]686[/URL] i.e. [URL="http://factorization.ath.cx/search.php?se=1&aq=507924&action=last20"]507924[/URL] terminates with the same number of digits as my first termination.
[URL="http://factorization.ath.cx/aliquot.php?type=1&aq=507924&big=1"]Graph[/URL]

The previous one to reach 115 digits, [URL="http://factorization.ath.cx/search.php?se=1&aq=151752&action=last20"]151752[/URL] was 'third place' for highest sequence that terminates, so this would be 4th largest being 3x smaller.

 RobertS 2009-09-16 14:27

[URL="http://factorization.ath.cx/search.php?se=1&aq=546504&action=last20&fr=&to="]546504[/URL] merges with 660 at i2378

 RobertS 2009-09-17 18:33

[URL="http://factorization.ath.cx/search.php?se=1&aq=552018&action=last20&fr=&to="]552018[/URL] is Prime!!!

 Greebley 2009-09-18 20:43

I noticed a difference between the DB and the summary page while doing a check.

569244 merges, but it doesn't seem to be listed. Perhaps someone forgot to report it? In any case it belongs here and on the summary page as merged.

Edit: Same with 957726, and 974120.

 henryzz 2009-09-19 07:34

[quote=Greebley;190255]I noticed a difference between the DB and the summary page while doing a check.

569244 merges, but it doesn't seem to be listed. Perhaps someone forgot to report it? In any case it belongs here and on the summary page as merged.

Edit: Same with 957726, and 974120.[/quote]
none of those sequences have are mentioned anywhere on mersenneforum
if the merges we found by our project then they need claiming

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