The mysterious exponent 16073131
 

See the thread [url=http://www.mersenneforum.org/showthread.php?s=&threadid=1213]Duplicate lines in HRF3.TXT[/url].

This exponent has been tested 9 times by the same machine, with a [i]different result each time[/i].

:alien: :alien: :alien: :alien: :alien: :alien: :alien: :alien: :alien:

No other machines have tested it yet.

DoubleCheck=16073131,66,1

Probably a write protected worktodo file (lucky for us).... If the shift count on all of the results are the same then write protected intermediate file as well.

[QUOTE][i]Originally posted by PrimeFun [/i]
[B]Probably a write protected worktodo file (lucky for us).... If the shift count on all of the results are the same then write protected intermediate file as well. [/B][/QUOTE]

Except the result, ie the residue, was [i]different[/i] all 9 times. A write-protected file can't explain that.

There are many cases where the same machine has tested an exponent over and over again (see the [url=http://www.mersenneforum.org/showthread.php?s=&threadid=1105]Runaway trains[/url] thread), but with the same result each time.

And this is not an error-prone machine: 0 bad, 40 good, 465 unverified needing a 2nd check, 26 unverified needing a 3rd or higher check [but 9 of those are this exponent].

This is certainly a curious situation...

I've added this to my worktodo.ini file... I'll post the result in a few days...

Another possible reason that a machine may retest the same exponent might be due to the Windows system restore function.

Here is a thread that I started when I found my machine retesting an exponent.
[URL=http://www.mersenneforum.org/showthread.php?s=&threadid=1066]Error 11 on version 22.6 -- what to do?[/URL]

[QUOTE][i]Originally posted by Xyzzy [/i]
[B]This is certainly a curious situation...

I've added this to my worktodo.ini file... I'll post the result in a few days... [/B][/QUOTE]
Hi all
I've done the same with my most reliable PC, as GP2 suggested, Pepe. Hear from me soon.
Regards

I'm 80% done with it...

I will need a week, roughly...

[FONT=courier new][SIZE=1]UID: Xyzzy/Xyzzy, M16073131 is not prime. Res64: 9D26E02798439FC4. WZ2: 364CE1ED,12517196,00000000[/SIZE] [/FONT]

Matches:

16073131,telos,CC304EA96,WX5,9D26E02798439FC4,9346279,00000000

:showoff: