Forum: Wagstaff PRP Search
2020-08-18, 22:15
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Replies: 7
Views: 4,152
Let's also note that the product of all s:
...
Let's also note that the product of all s:
for i=1 to q-2, when p==5 mod 6, equals 1
for i=1 to q-1, when p==1 mod 6, equals -1
We have a similar property when using Vbra-Reix, starting at...
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Forum: Wagstaff PRP Search
2020-08-18, 20:39
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Replies: 7
Views: 4,152
Looking at: https://oeis.org/A018844 it appears...
Looking at: https://oeis.org/A018844 it appears that Wagstaff and Mersenne numbers share half the same seeds: 4, 52, 724, ... {Each seed n is such that n-2=2*(m^2) and n+2=[3or6]*(p^2) where m and p...
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Forum: Wagstaff PRP Search
2020-08-18, 18:18
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Replies: 7
Views: 4,152
This holds also when 4 is replaced by: 52, 724, ...
This holds also when 4 is replaced by: 52, 724, 10084, 140452, 1956244, or 27246964 .
Found by means of (Pari/gp):
L = [5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 43, 61, 79, 101, 127, 167,...
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Forum: Wagstaff PRP Search
2019-11-22, 15:32
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Replies: 6
Views: 2,079
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Forum: Lounge
2016-02-17, 20:49
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Replies: 133
Views: 7,532
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Forum: Miscellaneous Math
2015-10-16, 19:02
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Replies: 27
Views: 2,102
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Forum: Miscellaneous Math
2015-09-11, 19:13
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Replies: 27
Views: 2,102
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Forum: Miscellaneous Math
2015-09-09, 20:41
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Replies: 27
Views: 2,102
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;
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Forum: Miscellaneous Math
2015-09-09, 13:23
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Replies: 27
Views: 2,102
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Forum: Miscellaneous Math
2015-09-08, 20:17
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Replies: 27
Views: 2,102
: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...
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Forum: Miscellaneous Math
2015-09-07, 21:53
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Replies: 27
Views: 2,102
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Forum: Miscellaneous Math
2015-09-07, 18:42
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Replies: 27
Views: 2,102
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...
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Forum: Miscellaneous Math
2015-09-07, 17:32
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Replies: 27
Views: 2,102
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...
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Forum: Miscellaneous Math
2015-09-06, 18:59
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Replies: 27
Views: 2,102
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...
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Forum: Miscellaneous Math
2015-09-05, 19:41
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Replies: 27
Views: 2,102
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...
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Forum: Miscellaneous Math
2015-09-05, 10:42
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Replies: 38
Views: 2,247
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Forum: Miscellaneous Math
2015-09-05, 10:30
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Replies: 27
Views: 2,102
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Forum: Miscellaneous Math
2015-09-05, 10:26
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Replies: 27
Views: 2,102
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Forum: Miscellaneous Math
2015-09-04, 21:33
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Replies: 27
Views: 2,102
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Forum: Miscellaneous Math
2015-09-04, 21:23
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Replies: 27
Views: 2,102
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Forum: Miscellaneous Math
2015-09-02, 18:53
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Replies: 38
Views: 2,247
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...
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Forum: Miscellaneous Math
2015-09-02, 18:43
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Replies: 38
Views: 2,247
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...
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Forum: Miscellaneous Math
2015-09-02, 18:23
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Replies: 38
Views: 2,247
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Forum: Miscellaneous Math
2015-09-02, 18:13
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Replies: 38
Views: 2,247
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Forum: Miscellaneous Math
2015-08-30, 21:50
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Replies: 10
Views: 782
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