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Forum: Wagstaff PRP Search 2019-11-22, 15:32
Replies: 6
Views: 556
Posted By T.Rex
(New ?) Wagstaff/Mersenne related property

Hi,

I have no idea if this property is new. If new, I even am not sure it may be useful.
Anyway.

Let q prime >3
q=2p+1 and thus p=\frac{q-1}{2}.

Let:
N_p=2^p+1 .
Forum: Lounge 2016-02-17, 20:49
Replies: 133
Views: 6,418
Posted By T.Rex
ADDRESS VERIFIED: YES MISSING: NONE PACKAGED:...

ADDRESS VERIFIED: YES
MISSING: NONE
PACKAGED: YES
SENT: 24 MAR
RECEIVED:
Forum: Miscellaneous Math 2015-10-16, 19:02
Replies: 27
Views: 1,429
Posted By T.Rex
I still think that an algorithm that produces...

I still think that an algorithm that produces only 3 kinds of numbers:
1) primes
2) composite numbers like the ones here below (only 1 small divisor equal to 2b-1)
3) cases in bold (like...
Forum: Miscellaneous Math 2015-09-11, 19:13
Replies: 27
Views: 1,429
Posted By T.Rex
I'm Hobbes ! A real Tiger !! Be afraid ! And read...

I'm Hobbes ! A real Tiger !! Be afraid ! And read again all Watterson's books in order to remember how dangerous I can be !!

;)
Forum: Miscellaneous Math 2015-09-09, 20:41
Replies: 27
Views: 1,429
Posted By T.Rex
Here is a modified code that shows the...

Here is a modified code that shows the pseudoprimes such that N=0 mod(2*c-1) :

CEk2c(k,c,g)=
{
a=6;
h=a/2;
if(c>0,s=1,s=-1;c*=-1);
for(n=c<<1+1,g,
N=k<<n+s*c;
e=c%4;
Forum: Miscellaneous Math 2015-09-09, 13:23
Replies: 27
Views: 1,429
Posted By T.Rex
Hummmmm I understand your point. However, don't...

Hummmmm I understand your point.
However, don't you think that there are other ways for finding new stuff than using pure Math proof ? Is there a place for experimenting ? Years ago, before...
Forum: Miscellaneous Math 2015-09-08, 20:17
Replies: 27
Views: 1,429
Posted By T.Rex
:surrender Hummm Sometimes, I'm saying myself...

:surrender
Hummm Sometimes, I'm saying myself that I should go back to photography and forget Maths, where I was not so good even before I forgot so many things !
:surrender
Anyway, thanks for the...
Forum: Miscellaneous Math 2015-09-07, 21:53
Replies: 27
Views: 1,429
Posted By T.Rex
There are also pseudo primes for c=89, but not...

There are also pseudo primes for c=89, but not with 81, 87, 105, with the following bounds:
for(k=1,300,CEk2c(k,89,300)) :
133*2^262+89
221*2^291+89
266*2^261+89
Forum: Miscellaneous Math 2015-09-07, 18:42
Replies: 27
Views: 1,429
Posted By T.Rex
for(k=1,100,for(c=0,50,CEk2c(k,2*c+1,100))) :...

for(k=1,100,for(c=0,50,CEk2c(k,2*c+1,100))) : there are only 13 pseudoprimes out of 5588 numbers verifying the test; including 5575 primes: 0.23% of pseudoprimes. Out of a total of 125,000 numbers N...
Forum: Miscellaneous Math 2015-09-07, 17:32
Replies: 27
Views: 1,429
Posted By T.Rex
If we use the test as-is: ( if(s==sn && !...

If we use the test as-is: ( if(s==sn && ! isprime(N) ), it produces pseudoprimes, like: 1*2^3+1 or 98*2^79+17 .

for(k=1,100,for(c=0,50,CEk2c(k,2*c+1,100))) : produces 34 pseudoprimes.

But, if...
Forum: Miscellaneous Math 2015-09-06, 18:59
Replies: 27
Views: 1,429
Posted By T.Rex
About proving the sufficiency, I think that an...

About proving the sufficiency, I think that an issue (as I already said) is that s can be equal to sn before i==n-1 .
Finding s(n-1)==sn only after n-1 iterations and not before is important I...
Forum: Miscellaneous Math 2015-09-05, 19:41
Replies: 27
Views: 1,429
Posted By T.Rex
I should read again the documentation of...

I should read again the documentation of PARI/gp... ;) However, I'm now involved with porting Ruby and Python3, and then Go, on AIX, so I'm fed up reading language documentation. So, I know very...
Forum: Miscellaneous Math 2015-09-05, 10:42
Replies: 38
Views: 1,462
Posted By T.Rex
Yes. I've seen that recently. Robert Gerbicz used...

Yes. I've seen that recently. Robert Gerbicz used 3/2 mod N and Anton Vrba used 6, in 2008 October.
See: Gerbicz (https://trex58.files.wordpress.com/2009/01/wagstaffandfermat.pdf) and Vrba ...
Forum: Miscellaneous Math 2015-09-05, 10:30
Replies: 27
Views: 1,429
Posted By T.Rex
I do not think that this will speed up the...

I do not think that this will speed up the computation, since PARI goes in Stack overflow quickly. Modulo helps to keep s small.
Forum: Miscellaneous Math 2015-09-05, 10:26
Replies: 27
Views: 1,429
Posted By T.Rex
Ha ha ha ! No ! ;) I should have considered......

Ha ha ha ! No ! ;) I should have considered... but too busy with other stuff.
Forum: Miscellaneous Math 2015-09-04, 21:33
Replies: 27
Views: 1,429
Posted By T.Rex
Thanks to primus to have warned me about...

Thanks to primus to have warned me about Predrag's publication in StackExchange. :smile:
Forum: Miscellaneous Math 2015-09-04, 21:23
Replies: 27
Views: 1,429
Posted By T.Rex
Thumbs up Conjectured compositeness tests for N=k⋅2n±c by Predrag

Predrag (not sure he wants his name to appear since he published as "MathBot") has published a question in StackExchange...
Forum: Miscellaneous Math 2015-09-02, 18:53
Replies: 38
Views: 1,462
Posted By T.Rex
Here is what HC Williams and Mr Wagstaff had...

Here is what HC Williams and Mr Wagstaff had answered at the time I asked them some help:

Mr H.C. Williams :
"Because we cannot easily factor p-1 in your case, I am very doubtful that you will...
Forum: Miscellaneous Math 2015-09-02, 18:43
Replies: 38
Views: 1,462
Posted By T.Rex
Yes. Probably. However, there is no proof yet...

Yes. Probably. However, there is no proof yet that, if N is prime, it always verifies the property. It's good to know.
Moreover, he's close to the latest element of the sequence: 786441 . Greatest...
Forum: Miscellaneous Math 2015-09-02, 18:23
Replies: 38
Views: 1,462
Posted By T.Rex
Someone has posted a set of 4 much higher-level...

Someone has posted a set of 4 much higher-level conjectures k2^n ± c , which make use of Chebitchev functions that are connected to x^2-2 .
See: StackExchange...
Forum: Miscellaneous Math 2015-09-02, 18:13
Replies: 38
Views: 1,462
Posted By T.Rex
So, seed 6 seems to work too. Another Universal...

So, seed 6 seems to work too. Another Universal initial value.
Forum: Miscellaneous Math 2015-08-30, 21:50
Replies: 10
Views: 610
Posted By T.Rex
There is an issue with n==0 mod 3. Maybe 21...

There is an issue with n==0 mod 3. Maybe 21 should be used as seed instead of 13, which misses 2199.
More values are required.
Forum: Miscellaneous Math 2015-08-30, 20:35
Replies: 13
Views: 516
Posted By T.Rex
"They didn't know that it was impossible, so they...

"They didn't know that it was impossible, so they did it".
"Without deviation from the norm, progress is not possible".

Provide a Math proof, and I'll stop this obsession (as you said).
For now,...
Forum: Miscellaneous Math 2015-08-30, 20:10
Replies: 13
Views: 516
Posted By T.Rex
Explanation is not a proof. Explanation is only...

Explanation is not a proof. Explanation is only words. Would you mind writing a proof ?
Forum: Miscellaneous Math 2015-08-30, 20:07
Replies: 13
Views: 516
Posted By T.Rex
Thanks for the advice ! However, after the death...

Thanks for the advice ! However, after the death of my wife in 2006, I see a psychiatrist every week since 2007. If I have time, I'll talk with him about my Math obsession (as you said) this Thurday....
Showing results 1 to 25 of 911

 
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