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-   -   Subproject #4: 10k-50k sequences to 110 digits (https://www.mersenneforum.org/showthread.php?t=12610)

10metreh 2009-10-25 08:27

Subproject #4: 10k-50k sequences to 110 digits
 
Right then, here we go. Take sequences to 110 digits. The next subproject after this will probably be 50k-100k to 110 digits.

Sadly there will be very few driverless sequences in this subproject because Clifford Stern has worked on them, but we are hoping for a couple of terminations anyway.

[B]This subproject is complete! Subproject #6 has [url=http://www.mersenneforum.org/showthread.php?t=13625]started[/url].[/B]

unconnected 2009-10-25 09:15

Taking 11040, it's now size 109 with chance to escape from 2^4*31 driver.

10metreh 2009-10-25 09:19

[QUOTE=unconnected;193817]Taking 11040, it's now size 109 with chance to escape from 2^4*31 driver.[/QUOTE]

Tell us when it reaches 110, but keep it if it does escape.

Greebley 2009-10-25 13:45

Reserving 12048, 12960

unconnected 2009-10-25 16:29

[quote=10metreh;193818]Tell us when it reaches 110, but keep it if it does escape.[/quote]

Ok. 2^4*31 was gone on next iteration after I taking it, now 2^2 guide. And another interesting thing - c40 on P-1 with B1=11e4, it's quite rarely.

[code][Oct 25 2009, 19:21:42] Cofactor 35438288778883741901846977908834654106992920711709820109695229406373740167644758563654018774008812277932269 (107 digits)

[Oct 25 2009, 19:21:42] c107: running rho...

[Oct 25 2009, 19:21:42] c107: running P-1 at B1=11e4...
Using B1=110000, B2=39772318, polynomial x^1, x0=1361616734
Step 1 took 172ms
Step 2 took 93ms
********** Factor found in step 2: 4481460980912912496950001524923679495513
[Oct 25 2009, 19:21:42] *** c40 = 4481460980912912496950001524923679495513
[/code]

henryzz 2009-10-29 10:09

Reserving 11352, 11496, 11820, 11826

Greebley 2009-10-29 14:27

Done with 12048, 111 digits, 2^2*7

BigBrother 2009-10-29 20:53

Reserving 13056

unconnected 2009-10-29 21:19

Reserving 13800.

Greebley 2009-10-30 02:43

Done with 12960, 116 digits, 2^3*3*5

Reserving:
14676, 14706, 14922, 14970, 14994

10metreh 2009-10-30 09:31

[QUOTE=unconnected;193838]And another interesting thing - c40 on P-1 with B1=11e4, it's quite rarely.

[code][Oct 25 2009, 19:21:42] Cofactor 35438288778883741901846977908834654106992920711709820109695229406373740167644758563654018774008812277932269 (107 digits)

[Oct 25 2009, 19:21:42] c107: running rho...

[Oct 25 2009, 19:21:42] c107: running P-1 at B1=11e4...
Using B1=110000, B2=39772318, polynomial x^1, x0=1361616734
Step 1 took 172ms
Step 2 took 93ms
********** Factor found in step 2: 4481460980912912496950001524923679495513
[Oct 25 2009, 19:21:42] *** c40 = 4481460980912912496950001524923679495513
[/code][/QUOTE]

I have a couple of c41s and a c40 from P-1 in my logs, but this one is interesting:

[code][Sep 26 2009, 17:56:38] c73: running P-1 at B1=22e4...
Using B1=220000, B2=658485462, polynomial x^1, x0=2824457235
Step 1 took 359ms
Step 2 took 656ms
********** Factor found in step 2: 88002712661582093913481380044293027119959
[Sep 26 2009, 17:56:39] *** c41 = 88002712661582093913481380044293027119959[/code]

Not only would this also have been found with your P-1 bounds (I have b1scale = 2), but it split as p14 * p14 * p14, and it is still the largest 3-brilliant I have encountered in aliquot factorizations.

Also, a c40 in step 1, that would have been found in step 1 as low as B1 = 25033:

[code][Aug 21 2009, 11:43:26] c74: running P-1 at B1=22e4...
Using B1=220000, B2=658485462, polynomial x^1, x0=2143853441
Step 1 took 359ms
********** Factor found in step 1: 9100785968019815128384673673530868078937
[Aug 21 2009, 11:43:26] *** c40 = 9100785968019815128384673673530868078937[/code]

It was p9 * p10 * p11 * p12, which is the only time I have seen four factors this large with 1 digit between each.

And yes, if you ask, I have kept my logfiles as far back as 27 July. I like keeping them because they contain unusual factors like these.


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