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Forum: Math 2021-12-08, 01:39
Replies: 13
Views: 627
Posted By charybdis
No, it means exactly that, but in the ring of...

No, it means exactly that, but in the ring of integers mod M(p), rather than in the rational numbers.

The rational number 1/3 is the thing that makes 1 when you multiply it by 3. Similarly (3 mod...
Forum: CADO-NFS 2021-12-03, 22:07
Replies: 10
Views: 6,450
Posted By charybdis
Not to take anything away from your achievement,...

Not to take anything away from your achievement, but better parameter choices for polyselect would probably have saved you over 20% of sieving time. Extrapolating from the record polynomial scores...
Forum: Msieve 2021-12-01, 00:57
Replies: 189
Views: 54,547
Posted By charybdis
If we're adding scores for enormously large...

If we're adding scores for enormously large numbers, there's also this paper (https://hal.inria.fr/hal-01089507/document) which gives a polynomial for RSA-768 (232 digits) with score 7.690e-17,...
Forum: Cunningham Tables 2021-11-29, 23:13
Replies: 18
Views: 977
Posted By charybdis
Very nice! :cool: This is good enough that...

Very nice! :cool:

This is good enough that I'll stay away for longer than I was planning; there are lots of new base-2 Cunninghams to do...
Forum: Number Theory Discussion Group 2021-11-29, 23:06
Replies: 15
Views: 824
Posted By charybdis
As I'm sure you already know: For general p,...

As I'm sure you already know:

For general p, yes it can (eg p=17). For p a Mersenne prime, the answer is "no" for p greater than 7. By Euler's criterion, what we need to show is that a is a square...
Forum: Cunningham Tables 2021-11-28, 12:09
Replies: 18
Views: 7,687
Posted By charybdis
The base 2 extensions have now been added to the...

The base 2 extensions have now been added to the main tables, so as Batalov pointed out, there shouldn't be any reason not to do the "easy" sextic SNFS jobs anymore as credit will now be given.
...
Forum: Miscellaneous Math 2021-11-28, 12:03
Replies: 435
Views: 42,037
Posted By charybdis
Sorry to disappoint you. Robert [Don't...

Sorry to disappoint you.

Robert

[Don't want to start any arguments about whether I could *eventually* be a woman...]
Forum: Homework Help 2021-11-27, 16:32
Replies: 24
Views: 4,485
Posted By charybdis
And we can do this combinatorially too: both are...

And we can do this combinatorially too: both are the way of choosing k elements from a set of p elements, where we label one of those k elements as "special".
We get k*binomial(p,k) by choosing the...
Forum: Cunningham Tables 2021-11-27, 14:38
Replies: 18
Views: 977
Posted By charybdis
Perhaps. While I didn't see much dropoff up to...

Perhaps. While I didn't see much dropoff up to 40M, that doesn't mean there won't be by 400M. I suppose the prudent thing to do would be to run smallish ranges (100k?) at 40M and 400M and compare the...
Forum: Cunningham Tables 2021-11-27, 02:01
Replies: 18
Views: 977
Posted By charybdis
Depends if you set ropteffort very high. With...

Depends if you set ropteffort very high. With ropteffort=100 you'll be fine. 200 might potentially need more time on old/slow CPUs.
Your adrange is small enough that the length of the...
Forum: Homework Help 2021-11-26, 18:12
Replies: 24
Views: 4,485
Posted By charybdis
It depends what you mean by "reduced". Try...

It depends what you mean by "reduced". Try subtracting p from all the factors of the numerator, so p-1 turns into -1, p-2 into -2 etc, and see what that gives you.
Forum: Cunningham Tables 2021-11-26, 00:56
Replies: 18
Views: 977
Posted By charybdis
Polynomial selection for 2,2246M c221

This is one of only two remaining unambiguous GNFS numbers from the 1987 edition of the Cunningham book (base 2 <1200 bits), the other being 2,1109+ c225.

Bob Silverman suggested that the forum...
Forum: Cunningham Tables 2021-11-25, 20:08
Replies: 317
Views: 45,668
Posted By charybdis
Thank you for organising! Hope the linear algebra...

Thank you for organising! Hope the linear algebra goes smoothly.
Forum: Number Theory Discussion Group 2021-11-22, 21:15
Replies: 15
Views: 824
Posted By charybdis
This may be a valid PRP test (i.e. "p is prime"...

This may be a valid PRP test (i.e. "p is prime" => "condition holds") for q > 3. But you haven't proved anything in the other direction, namely "condition holds" => "p is prime". Things break down...
Forum: Cunningham Tables 2021-11-20, 18:57
Replies: 317
Views: 45,668
Posted By charybdis
Specifically it's the merge phase that's...

Specifically it's the merge phase that's multi-threaded. The rest of filtering is still single-threaded.



I remember reading somewhere that subsequent changes to CADO mean that this doesn't...
Forum: Cunningham Tables 2021-11-20, 16:46
Replies: 317
Views: 45,668
Posted By charybdis
The A/I value determines the size of the sieve...

The A/I value determines the size of the sieve region, i.e. how hard we search for relations at each special-Q. Higher A values will always have higher yield but worse rels/sec, but if you use too...
Forum: Cunningham Tables 2021-11-18, 23:39
Replies: 317
Views: 45,668
Posted By charybdis
Ah whoops, got these mixed up. Thanks for the...

Ah whoops, got these mixed up. Thanks for the correction!
Forum: Cunningham Tables 2021-11-18, 19:30
Replies: 317
Views: 45,668
Posted By charybdis
--bind-to none should only be needed with -np 2....

--bind-to none should only be needed with -np 2. --bind-to socket ought to have the same effect. When there are at least 3 processes OpenMPI will bind to socket by default. I have no clue why it...
Forum: Cunningham Tables 2021-11-18, 16:43
Replies: 317
Views: 45,668
Posted By charybdis
Very good! This confirms that A=30 was the right...

Very good! This confirms that A=30 was the right choice.



They were PMs, not posts :smile:



The answer to these is generally "maybe - give it a try". As long as the matrix remains above...
Forum: Cunningham Tables 2021-11-18, 12:53
Replies: 317
Views: 45,668
Posted By charybdis
You'll probably want to wait at least until a...

You'll probably want to wait at least until a matrix can be built with target_density=120; I expect VBCurtis will chime in later with his thoughts. Chances are if you tried TD=120 now you would get...
Forum: Cunningham Tables 2021-11-18, 11:54
Replies: 317
Views: 45,668
Posted By charybdis
My clients - and seemingly everyone else's - were...

My clients - and seemingly everyone else's - were unable to connect to the server for 3 hours last night, until about 07:10 your time. The logs show the same "Connection timed out" error as they do...
Forum: Cunningham Tables 2021-11-17, 20:59
Replies: 317
Views: 45,668
Posted By charybdis
Do rankings usually start at 0th place in...

Do rankings usually start at 0th place in Germany? :ermm:

(nice work again btw)
Forum: Cunningham Tables 2021-11-17, 13:29
Replies: 317
Views: 45,668
Posted By charybdis
Only in Greg's version of msieve, not the...

Only in Greg's version of msieve, not the "official" one.
Forum: NFS@Home 2021-11-17, 12:48
Replies: 1,873
Views: 164,064
Posted By charybdis
If you want something to try this out on, the...

If you want something to try this out on, the octic for 2,1180+ (diff. 285) sieves ~3 times faster than the quartic. Hard to do an exact comparison because yield drops off so much faster for the...
Forum: Cunningham Tables 2021-11-17, 12:35
Replies: 317
Views: 45,668
Posted By charybdis
Well I can't say I've ever tried to cat >200k...

Well I can't say I've ever tried to cat >200k files at once before :smile: Glad you found a good solution.

Of course I should have said "A5 to A0" rather than "A6 to A0" in my previous post. Not...
Showing results 1 to 25 of 548

 
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