mersenneforum.org  

Go Back   mersenneforum.org > Search Forums

Showing results 1 to 25 of 1000
Search took 0.23 seconds.
Search: Posts Made By: R. Gerbicz
Forum: Data 2021-02-24, 20:17
Replies: 549
Views: 73,836
Posted By R. Gerbicz
We had already a Prp-cf test on this: ...

We had already a Prp-cf test on this:
https://www.mersenne.org/report_exponent/?exp_lo=82939&exp_hi=&full=1

Notice that for N=(k*2^n+c)/d we're using a Fermat test using
base^d as base, then...
Forum: Miscellaneous Math 2021-02-20, 09:53
Replies: 4
Views: 162
Posted By R. Gerbicz
Repeated digit sum has a name:...

Repeated digit sum has a name: https://en.wikipedia.org/wiki/Digital_root .
Forum: Miscellaneous Math 2021-02-19, 20:18
Replies: 31
Views: 1,255
Posted By R. Gerbicz
Nice. You can negate that: x=F(n-1)/(F(n-2)-1)...

Nice. You can negate that: x=F(n-1)/(F(n-2)-1) mod F(n)

And in general: if n=u^4+1 then for x=(u^2+1)/u:
x^2==2 mod n.
Forum: Miscellaneous Math 2021-02-19, 15:18
Replies: 31
Views: 1,255
Posted By R. Gerbicz
Yes, that was my method.

Yes, that was my method.
Forum: Miscellaneous Math 2021-02-19, 10:36
Replies: 31
Views: 1,255
Posted By R. Gerbicz
And with linear algebra would you need...

And with linear algebra would you need primepi(100)+eps=25+eps relations ?
OK, take my challenge factor my GRSA100 [G means Gerbicz], n=p*q number with 100 digits. You can use "your" method, and...
Forum: Miscellaneous Math 2021-02-19, 08:22
Replies: 31
Views: 1,255
Posted By R. Gerbicz
Yes, used those known factors, but how? I mean if...

Yes, used those known factors, but how? I mean if M|N then we know only small squared residues mod M in the range of sqrt(M), but we need these residues mod N and not mod M. Ofcourse you can regard...
Forum: Miscellaneous Math 2021-02-19, 01:00
Replies: 31
Views: 1,255
Posted By R. Gerbicz
Actually it is easy, using the OP's other...

Actually it is easy, using the OP's other favourite number: F12 Fermat number [which was unfactored yesterday]:


N=2^4096+1;...
Forum: Information & Answers 2021-02-15, 17:10
Replies: 26
Views: 851
Posted By R. Gerbicz
Oh, yes that is even better what I've written,...

Oh, yes that is even better what I've written, and maybe: forcing that the server wouldn't give out the same prime exponent twice per day. In this way even if you have a fully factorized mp you would...
Forum: Information & Answers 2021-02-14, 23:39
Replies: 26
Views: 851
Posted By R. Gerbicz
Interesting topic. Still don't see a way, my...

Interesting topic. Still don't see a way, my failed approach in the prp(!) setup:

The key idea is to change the base after a successful mining to a random base with say 64 bits.
And then the new...
Forum: Homework Help 2021-02-13, 21:46
Replies: 3
Views: 265
Posted By R. Gerbicz
If x is composite then we know: ...

If x is composite then we know:
c*x/log(log(x))<phi(x)<=x-sqrt(x), where c>0 is a constant [c=0.25 is good for all x>6].

ok, not very elegant to use these, though this is still elementary.
With...
Forum: Chess 2021-01-31, 19:40
Replies: 12
Views: 888
Posted By R. Gerbicz
Yes, forget that above we need to store also the...

Yes, forget that above we need to store also the number of bits of x. Here 15 or 16 bits should be enough maybe for all games.
Forum: Chess 2021-01-31, 15:02
Replies: 12
Views: 888
Posted By R. Gerbicz
Even easier way if you want to encode only a...

Even easier way if you want to encode only a single/few game:
use a generalized number system, say in the i-th move you have only B[i] valid moves you have chosen the r[i]-th move from these. And...
Forum: Chess 2021-01-31, 13:02
Replies: 12
Views: 888
Posted By R. Gerbicz
You can reach almost the optimal log(13)/log(2)...

You can reach almost the optimal log(13)/log(2) bits difficulty when you have 13 possibilities
for a move. The idea is that for each p number of possibility maintain a seperate array to
extract the...
Forum: Chess 2021-01-17, 12:50
Replies: 2
Views: 301
Posted By R. Gerbicz
See:...

See: https://chess.stackexchange.com/questions/4490/maximum-possible-movement-in-a-turn
Forum: Puzzles 2021-01-04, 20:50
Replies: 13
Views: 933
Posted By R. Gerbicz
We need for a given x>0 that...

We need for a given x>0 that x=a+..+(a+b)=(2*a+b)*(b+1)/2 with a,b>0

So: 2*x=(2*a+b)*(b+1)
Notice that 2*a+b and b+1 has different parity, hence if x is a power of two
then this equation has no...
Forum: Forum Feedback 2020-12-26, 16:25
Replies: 4
Views: 631
Posted By R. Gerbicz
Also this thread??

Also this thread??
Forum: Programming 2020-12-25, 18:54
Replies: 37
Views: 10,692
Posted By R. Gerbicz
That is way slower than my brain, it is...

That is way slower than my brain, it is irreducible with Eisenstein's criterion using p=2, ref:
https://en.wikipedia.org/wiki/Eisenstein%27s_criterion
Forum: Math 2020-12-15, 00:53
Replies: 16
Views: 915
Posted By R. Gerbicz
The reason: 2^(E*2*p)==1 mod 2^p-1.

The reason: 2^(E*2*p)==1 mod 2^p-1.
Forum: Tales From the Crypt(o) 2020-12-13, 19:55
Replies: 7
Views: 824
Posted By R. Gerbicz
Probably not found, all of them looks like...

Probably not found, all of them looks like gibberish, but here it is:
using a wordlist of size=9027 [basically a 10k list, but deleted all words with length<4 that was not in a 4k list]. All...
Forum: y-cruncher 2020-12-08, 12:25
Replies: 49
Views: 29,065
Posted By R. Gerbicz
False, I've written this: "if you're claiming a...

False, I've written this:
"if you're claiming a world record then I would choose 1 million random positions and you should give the bits for each of these positions. The check: select say 20-25...
Forum: y-cruncher 2020-12-08, 10:59
Replies: 49
Views: 29,065
Posted By R. Gerbicz
That's why your suggested methods is just not...

That's why your suggested methods is just not working (needs to repeat the whole computation), but my proposed way is using much less time.
For comparison in this record size the BBP takes less than...
Forum: y-cruncher 2020-12-07, 14:05
Replies: 49
Views: 29,065
Posted By R. Gerbicz
So you would accept any(?) hash value as a proof,...

So you would accept any(?) hash value as a proof, say claiming 256T digits of Pi, and giving only sha256 as:

a19a6c3a75783b6b5deee64777873ae207764837e769eedbe9b4c485d94b2986
Forum: y-cruncher 2020-12-05, 18:08
Replies: 49
Views: 29,065
Posted By R. Gerbicz
There is no BBP type formula for Pi in base ten...

There is no BBP type formula for Pi in base ten [though there could be], https://en.wikipedia.org/wiki/Bailey%E2%80%93Borwein%E2%80%93Plouffe_formula .
But even giving only the last few bits would...
Forum: Programming 2020-11-29, 00:33
Replies: 37
Views: 10,692
Posted By R. Gerbicz
Try x^720-1. On an older Chrome it is just...

Try x^720-1. On an older Chrome it is just crashing, on Firefox after some computation it has given: "index out of bounds", the 2nd run is still computing and it is in the: "Computing LLL in matrix...
Forum: Puzzles 2020-11-26, 20:58
Replies: 34
Views: 2,164
Posted By R. Gerbicz
For Q2 the optimal is 9 terms (using 4 pieces of...

For Q2 the optimal is 9 terms (using 4 pieces of 13 and 5 pieces 666):

13-(666-(666+666)*(666+13*(13+13)))/666

and for Q1 the optimal is the above 8 terms.
Assuming that we would use "only"...
Showing results 1 to 25 of 1000

 
All times are UTC. The time now is 07:40.

Sat Feb 27 07:40:30 UTC 2021 up 86 days, 3:51, 0 users, load averages: 1.57, 1.76, 1.67

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.