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Forum: Factoring 2021-07-22, 16:28
Replies: 413
Views: 16,445
Posted By charybdis
So you ran t50 and then called yafu factor(),...

So you ran t50 and then called yafu factor(), which presumably ran at least another t50?
Forum: Factoring 2021-07-22, 14:59
Replies: 413
Views: 16,445
Posted By charybdis
Ah, so by preNFS you really mean the first stage...

Ah, so by preNFS you really mean the first stage of NFS. I suppose if we're being really strict about the meaning of the word "sieve" then polynomial selection is pre-NFS and postprocessing is...
Forum: Factoring 2021-07-22, 13:59
Replies: 413
Views: 16,445
Posted By charybdis
What do you mean by "preNFS"?

What do you mean by "preNFS"?
Forum: Factoring 2021-07-22, 12:17
Replies: 413
Views: 16,445
Posted By charybdis
As an SNFS job this is probably equivalent to a...

As an SNFS job this is probably equivalent to a GNFS in the low 160s. I've seen a few different estimates for ECM effort but for GNFS I usually go for c*digits with c = 0.31 or 0.32. For this number,...
Forum: Factoring 2021-07-21, 22:40
Replies: 521
Views: 96,392
Posted By charybdis
A rather lucky ECM factor from aliquot sequence...

A rather lucky ECM factor from aliquot sequence 2360:

Using B1=11000000, B2=35133391030, polynomial Dickson(12), sigma=1:2026970909
Step 1 took 12373ms
Step 2 took 5994ms
********** Factor...
Forum: CADO-NFS 2021-07-21, 11:37
Replies: 18
Views: 387
Posted By charybdis
The advantage for adjust_strategy=2 with integer...

The advantage for adjust_strategy=2 with integer I seems to get greater for larger jobs. I don't know why this happens, but it does. So if you're doing a big job then you definitely will want...
Forum: CADO-NFS 2021-07-20, 18:59
Replies: 18
Views: 387
Posted By charybdis
tasks.I = n corresponds to tasks.A = 2n-1, so...

tasks.I = n corresponds to tasks.A = 2n-1, so A=26 is between I=13 and I=14.

If you're using an even value of A, you should use adjust_strategy = 2 whatever the circumstances. For tasks.I (in...
Forum: CADO-NFS 2021-07-20, 17:42
Replies: 18
Views: 387
Posted By charybdis
The E-score is supposed to be directly...

The E-score is supposed to be directly proportional to yield for a fixed set of parameters, so you'd expect the number with the lower score here to take about 70% longer if the parameters remain the...
Forum: CADO-NFS 2021-07-20, 13:19
Replies: 18
Views: 387
Posted By charybdis
It was the 4-digit increase in GNFS equivalent...

It was the 4-digit increase in GNFS equivalent difficulty for a 3-digit increase in SNFS difficulty that surprised me. Judging by the E scores of the polynomials, I would have expected them to sieve...
Forum: Aliquot Sequences 2021-07-19, 16:47
Replies: 2,972
Views: 232,074
Posted By charybdis
I'd say go ahead. After all, a journey of a...

I'd say go ahead. After all, a journey of a thousand miles begins with a single step (or rather 12,000 steps...)
Forum: CADO-NFS 2021-07-19, 16:38
Replies: 18
Views: 387
Posted By charybdis
That's surprising. Can you post the params files...

That's surprising. Can you post the params files you used for each of these jobs?



The number of relations required is determined mainly by lpb0/lpb1: raising both by 1 roughly doubles the...
Forum: CADO-NFS 2021-07-19, 13:40
Replies: 18
Views: 387
Posted By charybdis
Unfortunately it's not linear. It depends on the...

Unfortunately it's not linear. It depends on the degree of the polynomial and which side you're sieving on (which reminds me: -sqside is another important optional command line flag for las), and...
Forum: Aliquot Sequences 2021-07-18, 23:13
Replies: 2,972
Views: 232,074
Posted By charybdis
I've run 11400@40e7, 13900@42e7 and 1100@1e9,...

I've run 11400@40e7, 13900@42e7 and 1100@1e9, which together with the curves already done adds up to just over t60. That's it for now.

Where do people want to go with this? Unless Ryan gets...
Forum: CADO-NFS 2021-07-18, 17:47
Replies: 18
Views: 387
Posted By charybdis
Depends how thoroughly you're test-sieving...

Depends how thoroughly you're test-sieving :smile:

If you're not going to be changing the parameters much then what wombatman suggests should be fine. If you're going to be testing lots of...
Forum: Miscellaneous Math 2021-07-18, 12:11
Replies: 41
Views: 632
Posted By charybdis
:soapbox: In the words of Joe Biden, "C'mon,...

:soapbox:

In the words of Joe Biden, "C'mon, man!"

Before you immediately accuse someone of malice, stop and think whether there might be any other explanation for what they've done.

It's...
Forum: Miscellaneous Math 2021-07-17, 21:07
Replies: 49
Views: 1,338
Posted By charybdis
You have misunderstood the point of my post. It...

You have misunderstood the point of my post. It was not intended to support your views. All I did was calculate the probabilities given by the LPW heuristic for each prime up to 103M and add up the...
Forum: Miscellaneous Math 2021-07-17, 16:58
Replies: 49
Views: 1,338
Posted By charybdis
Here's a comparison between the expected number...

Here's a comparison between the expected number of primes with each digit sum according to the LPW heuristic and the actual number observed, up to the current first testing limit of p=103580003....
Forum: Miscellaneous Math 2021-07-16, 17:15
Replies: 49
Views: 1,338
Posted By charybdis
Smaller Mersennes are much more likely to be...

Smaller Mersennes are much more likely to be prime, so this is about as useful as pointing out that most of the Mersenne prime exponents up to 100M are below 50M. :clap:



Hoping that I haven't...
Forum: Miscellaneous Math 2021-07-15, 14:09
Replies: 49
Views: 1,338
Posted By charybdis
Yes, the deviation from the heuristic may well be...

Yes, the deviation from the heuristic may well be statistically significant at the 2-sigma level, but I don't think that should be enough to change our views. If the new slope were to continue for...
Forum: Miscellaneous Math 2021-07-14, 23:06
Replies: 49
Views: 1,338
Posted By charybdis
You haven't answered any of my questions. I'm...

You haven't answered any of my questions. I'm going to assume you haven't tried generating random sets of exponents as I advised. If you had, you'd see that even when the heuristic is being used to...
Forum: Aliquot Sequences 2021-07-14, 12:36
Replies: 2,972
Views: 232,074
Posted By charybdis
Done 12000@15e7. Now running curves at 40e7 and...

Done 12000@15e7. Now running curves at 40e7 and 42e7.
Forum: Miscellaneous Math 2021-07-14, 12:23
Replies: 49
Views: 1,338
Posted By charybdis
No it isn't. There are good reasons for believing...

No it isn't. There are good reasons for believing it *might* be true, as detailed on the page I linked to. That's what it means to be a heuristic. Lenstra and Pomerance didn't pull the factor e^gamma...
Forum: Miscellaneous Math 2021-07-14, 01:36
Replies: 49
Views: 1,338
Posted By charybdis
We can use the Lenstra-Pomerance-Wagstaff...

We can use the Lenstra-Pomerance-Wagstaff heuristic (https://primes.utm.edu/mersenne/heuristic.html) to estimate the probability that 2^p-1 is prime. Using this, we can calculate the probability of...
Forum: Miscellaneous Math 2021-07-13, 18:03
Replies: 49
Views: 1,338
Posted By charybdis
This is a meaningless observation, for the same...

This is a meaningless observation, for the same reason that it's meaningless to note that the digit sums are all below 50.

Digit sums of Mersenne prime exponents (apart from 3 itself) can't be...
Forum: Aliquot Sequences 2021-07-13, 16:31
Replies: 2,972
Views: 232,074
Posted By charybdis
Moving on to t55...

Moving on to t55...
Showing results 1 to 25 of 358

 
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