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Forum: Miscellaneous Math 2021-04-18, 13:14
Replies: 15
Views: 310
Posted By charybdis
:no: The discussion in this thread is about...

:no:

The discussion in this thread is about when 9 is a quadratic residue mod n, not when n is a quadratic residue mod 9.

OP, you seem to have assumed we can use Euler's criterion to check...
Forum: Factoring 2021-04-15, 13:46
Replies: 7
Views: 312
Posted By charybdis
1/3 might be slightly higher than optimal,...

1/3 might be slightly higher than optimal, although what's best will depend on what software you're using for GNFS. I've used 0.32 when running ggnfs via YAFU (factmsieve.py would be similar), and...
Forum: NFS@Home 2021-04-14, 16:25
Replies: 121
Views: 12,213
Posted By charybdis
It scores the same because, to all intents and...

It scores the same because, to all intents and purposes, it is the same. If the algebraic poly is f (degree d) and the rational poly is g, then a relation is given by a pair (a,b) for which the...
Forum: NFS@Home 2021-04-14, 14:36
Replies: 121
Views: 12,213
Posted By charybdis
Sure, but not for any mathematical reason. If we...

Sure, but not for any mathematical reason. If we flip the sign of Y0 or Y1, then we flip the sign of the root, so if we also flip the signs of the odd-degree coefficients of the algebraic poly then...
Forum: NFS@Home 2021-04-14, 12:31
Replies: 121
Views: 12,213
Posted By charybdis
-17^34 is a root of both polys so this is fine.

-17^34 is a root of both polys so this is fine.
Forum: Data 2021-04-14, 03:00
Replies: 17
Views: 507
Posted By charybdis
P-1 is particularly useful for GIMPS because we...

P-1 is particularly useful for GIMPS because we can take advantage of the fact that all factors of 2^p-1 are of the form 2kp+1: we only need k to be smooth wrt B1/B2 in order to find the factor. P+1...
Forum: Number Theory Discussion Group 2021-04-13, 12:50
Replies: 7
Views: 110
Posted By charybdis
Indeed, and it's trivial to construct a...

Indeed, and it's trivial to construct a counterexample. But they are the same for ω(n), and in fact to prove the result I gave above one would want to deal with [$]\sum_{n\leq x}\omega(n)[/$] first,...
Forum: Number Theory Discussion Group 2021-04-13, 11:19
Replies: 7
Views: 110
Posted By charybdis
A fun exercise is to deduce from Mertens' theorem...

A fun exercise is to deduce from Mertens' theorem
[$$]\sum_{p\leq x}\frac{1}{p} = \log\log x + M + o(1)[/$$]
(where M is a constant) that
[$$]\sum_{n\leq x}|\omega(n)-\log\log n|^2 = O(x\log\log...
Forum: Aliquot Sequences 2021-04-11, 17:40
Replies: 2,957
Views: 207,971
Posted By charybdis
The c191 at line 12590 has survived ~half a t60...

The c191 at line 12590 has survived ~half a t60 so far and will soon be ready for GNFS; it's probably OK for the usual suspects to start poly selection now.

I suppose this is near the crossover...
Forum: YAFU 2021-04-11, 16:51
Replies: 18
Views: 732
Posted By charybdis
Looks good now. Thank you!

Looks good now. Thank you!
Forum: YAFU 2021-04-10, 12:58
Replies: 2
Views: 106
Posted By charybdis
The -B1ecm option only affects ecm(), not...

The -B1ecm option only affects ecm(), not factor().

You can use -work to specify how much ECM has already been run on a number: -work 30 would mean that ECM is already complete to the 30-digit...
Forum: YAFU 2021-04-10, 12:50
Replies: 12
Views: 377
Posted By charybdis
Each dependency is a single solution to the...

Each dependency is a single solution to the equations, i.e. a set of columns of the matrix which add to 0. At the end of the linear algebra you'll see something like "recovered 30 nontrivial...
Forum: Homework Help 2021-04-09, 23:14
Replies: 20
Views: 866
Posted By charybdis
Wrong. The factors of OP's number are ...

Wrong.

The factors of OP's number are
166447885293942400205064657834447096885456111524808377
1005632514199652040245190989819182186076324308468303514078693528739687994577
(I didn't find these...
Forum: YAFU 2021-04-09, 19:17
Replies: 18
Views: 732
Posted By charybdis
tune() doesn't segfault anymore, but I'm still...

tune() doesn't segfault anymore, but I'm still seeing a couple of issues. First it incorrectly detects a 64-bit linux system as 32-bit:
tune_info=Intel(R) Core(TM) i5-8500 CPU @...
Forum: Homework Help 2021-04-09, 12:55
Replies: 20
Views: 866
Posted By charybdis
Normally when I stumble across some crap I want...

Normally when I stumble across some crap I want to clean it up, not find its factors.

But if you desperately want to know the factors of this number, the best way is to find them yourself. There's...
Forum: YAFU 2021-04-09, 12:41
Replies: 18
Views: 732
Posted By charybdis
I don't think yafu's internal ecm can run...

I don't think yafu's internal ecm can run multithreaded on windows? Try using an external ecm binary and changing "ext_ecm=1000000000" in yafu.ini to something smaller like 10000 to make sure that it...
Forum: YAFU 2021-04-09, 01:58
Replies: 18
Views: 732
Posted By charybdis
I'm getting a segfault when attempting tune(), on...

I'm getting a segfault when attempting tune(), on both windows and linux:

===============================================================
======= Welcome to YAFU (Yet Another Factoring Utility)...
Forum: YAFU 2021-04-08, 11:26
Replies: 13
Views: 323
Posted By charybdis
You can set new defaults for yafu command line...

You can set new defaults for yafu command line options in yafu.ini: just add "psearch=avg" or "psearch=fast".
Forum: YAFU 2021-04-08, 02:13
Replies: 13
Views: 323
Posted By charybdis
Actually 417 seconds is yafu's deadline for the...

Actually 417 seconds is yafu's deadline for the whole search, which it prints to factor.log. This is different from the per-coefficient deadline, which only gets printed to the terminal as
deadline:...
Forum: Factoring 2021-04-07, 16:29
Replies: 23
Views: 789
Posted By charybdis
This might be related to the issue described in...

This might be related to the issue described in this thread (https://mersenneforum.org/showthread.php?t=26678) where yafu can sometimes spend way too long on polynomial selection.

(and even...
Forum: YAFU 2021-04-07, 16:26
Replies: 13
Views: 323
Posted By charybdis
I think this...

I think this (https://sourceforge.net/p/msieve/code/1023/) revision to msieve may be partly responsible? Particularly "deadline_per_coeff = 8640000", which essentially means each leading coefficient...
Forum: Aliquot Sequences 2021-04-07, 02:43
Replies: 2,957
Views: 207,971
Posted By charybdis
i12589

Next line has a c201, t45 is complete and I've set t50 to run overnight. Others are welcome to run curves at the t55 level.
Forum: YAFU 2021-04-05, 15:51
Replies: 12
Views: 377
Posted By charybdis
:lol::lol: I don't have much more to say...

:lol::lol:

I don't have much more to say about QS; LaurV and Dr Sardonicus have done a pretty good job of explaining the basics. The one thing I'd add to connect their two posts is that we can...
Forum: Hardware 2021-04-04, 21:41
Replies: 15
Views: 333
Posted By charybdis
The address changed a few months ago, you can...

The address changed a few months ago, you can sign up again from here (https://sympa.inria.fr/sympa/info/cado-nfs).
Forum: Hardware 2021-04-04, 21:26
Replies: 15
Views: 333
Posted By charybdis
I'm fairly sure it doesn't do this. There are...

I'm fairly sure it doesn't do this. There are options that can reduce memory usage while sacrificing quite a lot of speed, but the client doesn't invoke these automatically if there isn't enough...
Showing results 1 to 25 of 231

 
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