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Old 2011-12-16, 03:10   #727
LaurV
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Quote:
Originally Posted by EdH View Post
Already a change for one:

742740 has dropped one of the 5s. Within the last 20 lines, it has shed two 3s and two 5s. If it would just lose one more of each...
Ouch! One of the worst - read most persistent and fast increasing - drivers.... (2^3*(2^4-1))... If you can get rid of it, please let us know, I am yet to see how this driver can be broken... In fact, I am dying to see that, see my posts about 585000 in the reservation thread. Usually it holds for hundreds of terms....

Who said "Fear the 2^3*3*5" was damn right!
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Old 2011-12-16, 04:44   #728
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Quote:
Originally Posted by LaurV View Post
Ouch! One of the worst - read most persistent and fast increasing - drivers.... (2^3*(2^4-1))... If you can get rid of it, please let us know, I am yet to see how this driver can be broken... In fact, I am dying to see that, see my posts about 585000 in the reservation thread. Usually it holds for hundreds of terms....

Who said "Fear the 2^3*3*5" was damn right!
It proved too persistent! 2^3 * 3 * 5 has been steady for 15 lines. I let it go at 145/c132...
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Old 2011-12-17, 18:12   #729
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Quote:
Originally Posted by LaurV View Post
Ouch! One of the worst - read most persistent and fast increasing - drivers.... (2^3*(2^4-1))... If you can get rid of it, please let us know, I am yet to see how this driver can be broken... In fact, I am dying to see that, see my posts about 585000 in the reservation thread. Usually it holds for hundreds of terms....

Who said "Fear the 2^3*3*5" was damn right!
When I want to see how to lose a driver I look at small sequences in the database with the driver(2^3*3*5*7 works for 2^3*3*5). This can give a good idea how to lose it.
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Old 2011-12-19, 05:24   #730
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Quote:
Originally Posted by henryzz View Post
When I want to see how to lose a driver I look at small sequences in the database with the driver(2^3*3*5*7 works for 2^3*3*5). This can give a good idea how to lose it.
7 had nothing to do here, it comes and goes every few terms, unless you manage to get 2^2, when 3 and 5 will come and go and 2^2*7 will stay. What I call "driver" is always a number of the form 2^n*(2^(n+1)-1), with 2^(n+1)-1 being prime or not. These are the most persistent, no mater if they are perfect numbers or not (they are perfect numbers when 2^(n+1)-1 is prime, therefore a mersenne prime). Like 2*3, 2^2*7, 2^3*3*5, 2^4*31, 2^6*127... 2^10*23*89... 2^12*8191... etc. And even from this list, some of them are missing, they are only guides, for example 2^5*3^2*7 (i.e. n=5), this is not very persistent due to the even power of 3. They are more and more persistent as n is higher, and they make the sequence grow faster and faster when n is smaller and very smooth composite.
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Old 2011-12-19, 08:39   #731
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I posted a complete status update over in the reservation thread.
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Old 2011-12-19, 10:50   #732
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Quote:
Originally Posted by LaurV View Post
7 had nothing to do here
He meant, 2^3*3*5*7 (840) is an example of a sequence with the 2^3*3*5 driver. Examining that will help you see how the driver is lost (http://www.factordb.com/sequences.ph...nge&fr=0&to=21)
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Old 2011-12-19, 14:30   #733
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Aaaa! Ok. Now I understand what he said. Sorry for being dumb. Of course I am doing the same, studying sequences with small start numbers. I did this repeatedly, usually adding *19*37 after the drivers, or some equivalent.
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Old 2011-12-26, 19:48   #734
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releasing 412944, i2621, size 138, 2^2*3*5*7*619944163* C127
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Old 2011-12-28, 14:55   #735
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you'll be happy to know I got aliquot back up and running off my old PC, now to get prime95 to not be copied as a short cut and I might be up and running working on a C104 in this current sequence.

I should probably test the machine first and 2 I forgot to get perl again.

Last fiddled with by science_man_88 on 2011-12-28 at 15:03
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Old 2011-12-28, 17:45   #736
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Quote:
Originally Posted by science_man_88 View Post
you'll be happy to know I got aliquot back up and running off my old PC, now to get prime95 to not be copied as a short cut and I might be up and running working on a C104 in this current sequence.

I should probably test the machine first and 2 I forgot to get perl again.
I don't want to take everything away from slower machines but I now seem to have everything up and running.
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Old 2012-01-01, 07:28   #737
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And, just in time for the new year (in my time zone, anyway)... the elves have finished all the c108s in open unreserved sequences!

Happy new year, everyone!
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