mersenneforum.org  

Go Back   mersenneforum.org > Search Forums

Showing results 1 to 25 of 1000
Search took 0.19 seconds.
Search: Posts Made By: R. Gerbicz
Forum: Number Theory Discussion Group 2021-06-10, 01:05
Replies: 8
Views: 489
Posted By R. Gerbicz
a+b*I=1 looks like good for every f.

a+b*I=1 looks like good for every f.
Forum: Puzzles 2021-06-06, 00:36
Replies: 20
Views: 1,198
Posted By R. Gerbicz
An offline version of the puzzle, where you need...

An offline version of the puzzle, where you need to give all of your guesses in advance,
so you can profit nothing from the previous answers.
For n=10 here it is a solution that is using "only" 23...
Forum: Conjectures 'R Us 2021-06-04, 01:02
Replies: 945
Views: 108,371
Posted By R. Gerbicz
We are expecting that basically all of these (say...

We are expecting that basically all of these (say >1000 digits) Prps are really primes, so not composite.
Forum: Conjectures 'R Us 2021-06-04, 00:50
Replies: 945
Views: 108,371
Posted By R. Gerbicz
Not very surprising.

Not very surprising.
Forum: Puzzles 2021-06-02, 22:49
Replies: 20
Views: 1,198
Posted By R. Gerbicz
You need at least (1-eps)*n guesses on average...

You need at least (1-eps)*n guesses on average (for fixed eps>0 and for that large n).
Proof:
On the k-th level (after k guesses) there are at most (n+1)^k nodes, because each answer could be only...
Forum: YAFU 2021-06-02, 21:12
Replies: 7
Views: 313
Posted By R. Gerbicz
A small bug, on line=76 we need: ...

A small bug, on line=76 we need:

while(mpz_sgn(S)!=0){

since in the next line we'll divide by S
[in most cases we won't reach S=0 so the full continued fraction expansion because we exit much...
Forum: YAFU 2021-06-02, 20:59
Replies: 7
Views: 313
Posted By R. Gerbicz
Yes, you can use/modify etc. the code.

Yes, you can use/modify etc. the code.
Forum: YAFU 2021-06-02, 02:07
Replies: 7
Views: 313
Posted By R. Gerbicz
OK, here it is a solution, thought that it is a...

OK, here it is a solution, thought that it is a much easier code.
In a few seconds:

gerbicz@gerbicz-MS-7972:~/gmp-6.1.2$ ./f...
Forum: YAFU 2021-06-01, 21:41
Replies: 7
Views: 313
Posted By R. Gerbicz
Right, that divisor doesn't speed up the...

Right, that divisor doesn't speed up the factorisation, but here the problem is how to find that polynom if the user gives N=n/d and not the better form n.
Let me work out, but it is possible to...
Forum: YAFU 2021-06-01, 20:27
Replies: 7
Views: 313
Posted By R. Gerbicz
What about the N=n/d numbers? For example: ...

What about the N=n/d numbers? For example:

b=4241;
x=b^15;
N=(902367*x^5-2361274*x^4+32179627*x^3-45454704*x^2+545121457701*x+16647954129297)/36417887568782;
here:...
Forum: Viliam Furik 2021-05-30, 23:00
Replies: 7
Views: 289
Posted By R. Gerbicz
That would mean 1M bucks for you: ...

That would mean 1M bucks for you: https://en.wikipedia.org/wiki/Millennium_Prize_Problems. Maybe that is before tax, but I'm not really a tax expert here.
And instead of you I'd stick to these...
Forum: Software 2021-05-30, 12:45
Replies: 27
Views: 6,382
Posted By R. Gerbicz
That expensive ECC memory doesn't detect...

That expensive ECC memory doesn't detect (computational) FFT errors when you're using floating point FFT. My check detects those errors also, so you don't need to use suboptimal larger FFT size or...
Forum: Miscellaneous Math 2021-05-22, 20:26
Replies: 33
Views: 1,168
Posted By R. Gerbicz
It is: f(p)=p*log(p)*log(log(p))

It is:

f(p)=p*log(p)*log(log(p))
Forum: Miscellaneous Math 2021-05-21, 21:09
Replies: 33
Views: 1,168
Posted By R. Gerbicz
No, there should be really no connection. And...

No, there should be really no connection.
And likely there are infinitely many p, for that Mp is a Mersenne prime and p+2 is also a prime [the same is true for p-2], the heuristic calc using the...
Forum: Math 2021-05-15, 20:55
Replies: 2
Views: 476
Posted By R. Gerbicz
Multiple (prp) test at once?

When you are loading from a precomputed cos/sin table at fft or compute these in-fly then you could reuse these values. Basically hide/halve this computation cost [or just the cost of load] if you'd...
Forum: Lounge 2021-05-14, 23:50
Replies: 22
Views: 1,051
Posted By R. Gerbicz
That is true. For any N if you consider the b...

That is true.
For any N if you consider the b bases for that N is a Fermat pseudoprime then these bases form a group in Z_N.
For Mersenne numbers this means that 2^n is such a base, because mp is a...
Forum: Lounge 2021-05-04, 08:36
Replies: 40
Views: 3,268
Posted By R. Gerbicz
Thought that it is puzzle similar to: ...

Thought that it is puzzle similar to:
https://www.mersenneforum.org/showthread.php?t=4756
Forum: Data 2021-05-03, 21:56
Replies: 23
Views: 1,473
Posted By R. Gerbicz
Doesn't worth it, the best candidates: ?...

Doesn't worth it, the best candidates:

? polcyclo(3,q)
%23 = q^2 + q + 1
? polcyclo(4,q)
%24 = q^2 + 1
? polcyclo(6,q)
%25 = q^2 - q + 1

It is still doesn't divisible by p and you have...
Forum: Software 2021-04-28, 11:09
Replies: 312
Views: 28,740
Posted By R. Gerbicz
Exactly, add to that there is no error check in...

Exactly, add to that there is no error check in P-1. You could get a partial error check in stage one if you are doing a mixed prp/pm1 test, what gpuowl is doing. I could be wrong but you could also...
Forum: Software 2021-04-27, 13:57
Replies: 312
Views: 28,740
Posted By R. Gerbicz
This is still doesn't find q in the first test. ...

This is still doesn't find q in the first test.
More greedy run, try:
Pplus1=N/A,1,2,86743,-1,86742,2000000,1,40
Pplus1=N/A,1,2,86743,-1,86743,2000000,1,40

Only the 2nd one finds the...
Forum: GMP-ECM 2021-04-25, 19:48
Replies: 6
Views: 1,887
Posted By R. Gerbicz
There is a neat trap here, how you...

There is a neat trap here, how you should/shouldn't choose the seeds, if we remain at Wikipedia's writing:
would you choose these starting values: D=3; D=77; and then D=51975 after two failures?...
Forum: Software 2021-04-24, 23:29
Replies: 312
Views: 28,740
Posted By R. Gerbicz
Have you included p as a factor in the p+1 (!!)...

Have you included p as a factor in the p+1 (!!) method? Looks like not...
If really not then you will find no p-1 factors where p>B1 (unless with some luck), and all other factors except at most one...
Forum: And now for something completely different 2021-04-21, 20:05
Replies: 63
Views: 4,410
Posted By R. Gerbicz
Much less extra cost, say you want a^(b^n) mod N...

Much less extra cost, say you want a^(b^n) mod N using error checking, then choose e>0 and set a larger new base: B=b^e, for simplicity assume that e divides n, then

a^(b^n)=a^(B^(n/e))

and you...
Forum: Science & Technology 2021-04-19, 10:29
Replies: 227
Views: 14,121
Posted By R. Gerbicz
Today got the first dose of AstraZeneca. Need...

Today got the first dose of AstraZeneca.
Need 12 weeks for the 2nd dose.
Forum: Math 2021-04-15, 13:59
Replies: 10
Views: 6,523
Posted By R. Gerbicz
Yes, c is irrational, but not algebraic, so you...

Yes, c is irrational, but not algebraic, so you can't apply https://en.wikipedia.org/wiki/Roth%27s_theorem . Quite a known constant, so there could be proven theorem on good/best approx for c.
Showing results 1 to 25 of 1000

 
All times are UTC. The time now is 01:37.

Thu Jun 17 01:37:09 UTC 2021 up 19 days, 23:24, 0 users, load averages: 2.09, 1.81, 1.69

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, 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.