Small request
 

Given the various 'complete this range to X digits' projects, it would be very nice to see the size of the last known term in an aliquot sequence (rather than the size of its unfactored cofactor) in the overview page. Is that something that could be implemented? Obviously I can kludge it by scraping the overview page and following links, but that's a lot more load on the site.

[QUOTE=Mini-Geek;205518]Looks like it's fine to me.
[url]http://factordb.com/search.php?se=1&aq=947076[/url]
Maybe it was a problem fixable with the "Repair sequence" button, and someone did so without telling you?[/QUOTE]I did try the repair option myself 2 or 3 times to no avail.

[QUOTE=frmky;202470]Rather than fix them all manually, it might be easier to implement a "Retest Primality" button. There is a legion of volunteers here willing to hunt down the bad entries and click the button.[/QUOTE]

I also like the idea of this Retest primality button.
Just trial division up to some thousand and a fermat etst to the base 2, 3 and one more random number. That is very quick and all composites can be revealed.

In the very rare case of a strong pseudoprime number it is still possible to contact the administrator.

By the way: There is a simple way to find most of the broken aliquot sequences:
Go to the factor database, choose "squence overview", show only sequences ending with a prime, start with 2 and click "Ends with" (it sorts the primes descending). Large primes are very rare, so all P20 an larger are suspicious.

Now:
Start Length End Ends with
794280 830 Prime P107
794196 438 Prime P106
789090 597 Prime P101
789740 608 Prime P100
790248 1278 Prime P91
792756 703 Prime P90
790884 1193 Prime P89
794880 560 Prime P85
792864 887 Prime P85
792820 835 Prime P85
791196 1853 Prime P83
789816 1030 Prime P82

That works if a whole line has been set as prime, but it doesn't if a remaining composite (not the whole line) has been set prime.

true.

I noticed that normally the remaining composite was et prime and then the whole even next exponent. So we have to repair 2 indexes of every sequence. (Actually the last "prime" index would change anyway)

Until now i did not see a sequence where only the remaining composite was set prime. I assume that aliqeit would detect that while veifying when starting factoring.

Results uploading
 

Hi. I uploaded some results to the db. [URL="http://verity.ig.fi/workerstatus.html"]Here[/URL] is snapshot from the worker status page. :smile:

Sequence 552150, the longest single sequence, seems to have disappeared from the database. If you try to show the whole sequence, only line 8197 appears. Is there hacking going on?

Is the DB down? I can not Report Factors

[url]http://factordb.com/search.php?query=159[/url]
[url]http://factordb.com/search.php?se=1&aq=824768[/url]

The DB has 159 listed as "C" (composite with no known factors) even though it already knows it's 3*53. This is holding up Aliquot sequence 824768 at line 918. I can't find a way to fix this. Syd, can you please get 159 set straight?

The same problem with the factorization of 159 exists with Home Prime base 5 of 675, index 41.

Is there a nicer way of doing

(((x + (1-(0-1)^x)/2))/2)!+(0-1)^x

to get x! \pm 1 ?