mersenneforum.org Subproject #4: 10k-50k sequences to 110 digits
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 2009-10-25, 08:27 #1 10metreh     Nov 2008 91216 Posts 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. This subproject is complete! Subproject #6 has started. Last fiddled with by 10metreh on 2010-07-28 at 07:21 Reason: updating
 2009-10-25, 09:15 #2 unconnected     May 2009 Russia, Moscow 255510 Posts Taking 11040, it's now size 109 with chance to escape from 2^4*31 driver. Last fiddled with by 10metreh on 2010-05-09 at 17:03
2009-10-25, 09:19   #3
10metreh

Nov 2008

2×33×43 Posts

Quote:
 Originally Posted by unconnected Taking 11040, it's now size 109 with chance to escape from 2^4*31 driver.
Tell us when it reaches 110, but keep it if it does escape.

 2009-10-25, 13:45 #4 Greebley     May 2009 Dedham Massachusetts USA 3·281 Posts Reserving 12048, 12960
2009-10-25, 16:29   #5
unconnected

May 2009
Russia, Moscow

5·7·73 Posts

Quote:
 Originally Posted by 10metreh Tell us when it reaches 110, but keep it if it does escape.
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

Last fiddled with by unconnected on 2009-10-25 at 16:31

 2009-10-29, 10:09 #6 henryzz Just call me Henry     "David" Sep 2007 Cambridge (GMT/BST) 5,857 Posts Reserving 11352, 11496, 11820, 11826
 2009-10-29, 14:27 #7 Greebley     May 2009 Dedham Massachusetts USA 3×281 Posts Done with 12048, 111 digits, 2^2*7
 2009-10-29, 20:53 #8 BigBrother   Feb 2005 The Netherlands 2×109 Posts Reserving 13056
 2009-10-29, 21:19 #9 unconnected     May 2009 Russia, Moscow 5·7·73 Posts Reserving 13800.
 2009-10-30, 02:43 #10 Greebley     May 2009 Dedham Massachusetts USA 34B16 Posts Done with 12960, 116 digits, 2^3*3*5 Reserving: 14676, 14706, 14922, 14970, 14994
2009-10-30, 09:31   #11
10metreh

Nov 2008

2×33×43 Posts

Quote:
 Originally Posted by unconnected 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
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
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
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.

Last fiddled with by 10metreh on 2009-10-30 at 09:35

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