mersenneforum.org  

Go Back   mersenneforum.org > New To GIMPS? Start Here! > Information & Answers

Reply
 
Thread Tools
Old 2008-08-21, 11:09   #1
Unregistered
 

19·73 Posts
Post list of untouched exponents

how to get the list of all untouched exponents?
  Reply With Quote
Old 2008-08-21, 13:15   #2
Uncwilly
6809 > 6502
 
Uncwilly's Avatar
 
"""""""""""""""""""
Aug 2003
101×103 Posts

212468 Posts
Default

If you mean all that have had no testing on them, that list is infinite. The exponents are all prime numbers, of which there are infinitely many.

What area are you concerned with, 'low', those that have not yet been LL tested? Or higher, those that have had no trial factoring effort?
Uncwilly is online now   Reply With Quote
Old 2008-08-22, 02:54   #3
cheesehead
 
cheesehead's Avatar
 
"Richard B. Woods"
Aug 2002
Wisconsin USA

160248 Posts
Default

Quote:
Originally Posted by Unregistered View Post
how to get the list of all untouched exponents?
Here's one way, though it's tedious:

Go to the Version 5 server (still in beta test) at http://v5www.mersenne.org/.

Click on "Exponent Status" under the "Results Queries" heading in the left-side column (that takes you to http://v5www.mersenne.org/report_exponent/).

There, you can get the current status (prime, factored, no factor below 2^xx, no factor to P-1 limits, verified LL-tested, unverified LL-tested) of up to 100 candidates at a time, within a range you specify.

(Currently, it won't report on exponents greater than 1,000,000,000.)

Last fiddled with by cheesehead on 2008-08-22 at 03:03
cheesehead is offline   Reply With Quote
Old 2008-08-22, 06:59   #4
Batalov
 
Batalov's Avatar
 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2

22·3·7·109 Posts
Default

Ostensibly (except for some legacy untouchable ranges where weird things happen sometimes), at this time, every exponent under 1,000,000,000 was touched.

(There were some untouched exponents even two monts ago. Then typical TF jobs were TF to 60 bits above 720,000,000; then 800,000,000+ then some lower ranges... But now the typical factoring jobs are TF from 60 to 64 bits in the 171,000,000+ range - http://v5www.mersenne.org/report_recent_cleared/ Apparenly, all was touched, otherwise server would have reassigned it to someone.)

If you will find some, it will be interesting in some sense.
Batalov is offline   Reply With Quote
Old 2008-08-22, 08:50   #5
ET_
Banned
 
ET_'s Avatar
 
"Luigi"
Aug 2002
Team Italia

13·367 Posts
Default

If you look at Will Edgington's tables of factors, you'll see that the factors sequence grows for exponents well over 3 billions. I'm pretty sure Will did some factoring work (though at very low bit depth) on all of them.

Luigi
ET_ is offline   Reply With Quote
Old 2008-08-22, 16:26   #6
R.D. Silverman
 
R.D. Silverman's Avatar
 
Nov 2003

26×113 Posts
Default

Quote:
Originally Posted by Unregistered View Post
how to get the list of all untouched exponents?

Literally impossible. The list is infinite.
R.D. Silverman is offline   Reply With Quote
Old 2008-08-22, 21:08   #7
davieddy
 
davieddy's Avatar
 
"Lucan"
Dec 2006
England

193316 Posts
Default

Quote:
Originally Posted by R.D. Silverman View Post
Literally impossible. The list is infinite.
See post 2
davieddy is offline   Reply With Quote
Old 2008-08-22, 22:00   #8
cheesehead
 
cheesehead's Avatar
 
"Richard B. Woods"
Aug 2002
Wisconsin USA

22×3×599 Posts
Default

Quote:
Originally Posted by Batalov View Post
Apparenly, all was touched, otherwise server would have reassigned it to someone.
Correct. Some folks did indeed do a systematic TF up to 2^60 on all unfactored exponents up to 1,000,000,000.

---

For those new to the idea of trial-factoring Mersennes with larger exponents than the few-million we've been used to discussing:

Note that TF up to 2^60 on an exponent around 999,000,000 is roughly a thousand times as fast than a TF to 2^60 on an exponent around 999,000. Why? Because the potential divisors are about a thousand times as far apart for the former than for the latter, as one can deduce from the 2kn+1 requirement, so there are only one one-thousandth as many to test in the range of factor sizes up to 2^60.

It's true that there's a logarithmic factor in individual trial-division times, but that's much less significant than the linear-with-exponent decrease in number of potential candidates to be tested.

Last fiddled with by cheesehead on 2008-08-22 at 22:04
cheesehead is offline   Reply With Quote
Old 2008-08-23, 05:24   #9
ckdo
 
ckdo's Avatar
 
Dec 2007
Cleves, Germany

2×5×53 Posts
Default

Quote:
Originally Posted by cheesehead View Post
Correct. Some folks did indeed do a systematic TF up to 2^60 on all unfactored exponents up to 1,000,000,000.
Most have actually only been TF'd to 2⁵⁶. Getting them all to 2⁶⁰ is a task which will take months, if not years, to complete.
ckdo is offline   Reply With Quote
Old 2008-08-23, 07:01   #10
S485122
 
S485122's Avatar
 
Sep 2006
Brussels, Belgium

30738 Posts
Default

Quote:
Originally Posted by ckdo View Post
Most have actually only been TF'd to 2⁵⁶. Getting them all to 2⁶⁰ is a task which will take months, if not years, to complete.
256 and 260 respectively (if I decode it well)

Jacob
S485122 is offline   Reply With Quote
Old 2008-08-23, 11:03   #11
ATH
Einyen
 
ATH's Avatar
 
Dec 2003
Denmark

32·331 Posts
Default

Quote:
Originally Posted by cheesehead View Post
Note that TF up to 2^60 on an exponent around 999,000,000 is roughly a thousand times as fast than a TF to 2^60 on an exponent around 999,000. Why? Because the potential divisors are about a thousand times as far apart for the former than for the latter, as one can deduce from the 2kn+1 requirement, so there are only one one-thousandth as many to test in the range of factor sizes up to 2^60.
Which is why it would make more sense to keep track if the bitrange of k during TF instead of bitrange of 2kn+1.

Last fiddled with by ATH on 2008-08-23 at 11:03
ATH is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
List of available exponents sanaris PrimeNet 8 2018-04-06 04:31
List of recent exponents that have been passed out jasong PrimeNet 5 2007-05-18 22:56
Unreserving exponents(these exponents haven't been done) jasong Marin's Mersenne-aries 7 2006-12-22 21:59
List of primes Primeinator Math 18 2005-03-20 00:50
Who has a list? Ice9 Math 9 2004-01-27 16:32

All times are UTC. The time now is 00:18.

Wed Nov 25 00:18:54 UTC 2020 up 75 days, 21:29, 4 users, load averages: 2.08, 2.57, 2.39

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.