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 Showing results 1 to 25 of 1000 Search took 0.33 seconds. Search: Posts Made By: paulunderwood
 Forum: Miscellaneous Math 2021-12-07, 02:09 Replies: 35 Views: 2,317 Posted By paulunderwood n=2^44497-1;if(1==0&&Mod(3,n)^n==3) is... n=2^44497-1;if(1==0&&Mod(3,n)^n==3) is instant.
 Forum: Miscellaneous Math 2021-12-06, 19:41 Replies: 35 Views: 2,317 Posted By paulunderwood Apart from parenthesis and operator precedence,... Apart from parenthesis and operator precedence, things are parsed left to right, except for a few like "=" and "^" in Pari/GP (https://pari.math.u-bordeaux.fr/dochtml/html-stable/operators.html)...
 Forum: Homework Help 2021-12-06, 18:31 Replies: 9 Views: 146 Posted By paulunderwood :redface: :redface:
 Forum: Homework Help 2021-12-06, 11:21 Replies: 9 Views: 146 Posted By paulunderwood c=0;forprime(p=3,10^8,V=digits(p,3);W=[0,0,0];for(... c=0;forprime(p=3,10^8,V=digits(p,3);W=[0,0,0];for(v=1,#V,W[V[v]+1]++);if(W[3]==W[2]+W[1],c++));c 187914
 Forum: Miscellaneous Math 2021-12-06, 01:14 Replies: 7 Views: 111 Posted By paulunderwood To fool these "semi Euler" PRP tests, find a... To fool these "semi Euler" PRP tests, find a prime number with kronecker(2,n)==-1 and kronecker(-1,n)==-1 respectively.... The first: T(q)={Wq=3*2^2-1;S0=2^3;S=S0;print("q=...
 Forum: Miscellaneous Math 2021-12-05, 22:42 Replies: 7 Views: 111 Posted By paulunderwood Nor Riesel ... Nor Riesel q=4;Wq=557*2^q-1;S0=2^557;print(q," ",Wq);print(Mod(S0,Wq));S=S0;for(i=1,q,S=Mod(S^2,Wq);print(S)) 4 8911 ...
 Forum: Miscellaneous Math 2021-12-05, 22:19 Replies: 7 Views: 111 Posted By paulunderwood q=4;Wq=35*2^q+1;S0=2^35;print(q,"... q=4;Wq=35*2^q+1;S0=2^35;print(q," ",Wq);print(Mod(S0,Wq));S=S0;for(i=1,q,S=Mod(S^2,Wq);print(S));print(S==S0) 4 561 ...
 Forum: Miscellaneous Math 2021-12-05, 21:52 Replies: 7 Views: 111 Posted By paulunderwood q=1;Wq=80*7^1+1;S0=7^80;print(q,"... q=1;Wq=80*7^1+1;S0=7^80;print(q," ",Wq);print(Mod(S0,Wq));S=S0;for(i=1,q,S=Mod(S^7,Wq);print(S));print(S==S0) 1 561 ...
 Forum: Riesel Prime Search 2021-12-03, 22:50 Replies: 74 Views: 28,141 Posted By paulunderwood A slightly smaller one: 69* 2^14977631 - 1... A slightly smaller one: 69* 2^14977631 - 1 (https://primes.utm.edu/primes/page.php?id=133013) :banana:
 2021-11-28, 22:16 Replies: 17 Views: 7,783 Posted By paulunderwood Another way to do it with Pari-GP is... Another way to do it with Pari-GP is 2^89\10^2%10^21 where the infix operator \ gives the quotient.
 Forum: Miscellaneous Math 2021-11-28, 14:42 Replies: 431 Views: 41,282 Posted By paulunderwood Sorry for the confusion. I was just referring to... Sorry for the confusion. I was just referring to Tucker's blunder in general.
 Forum: Miscellaneous Math 2021-11-28, 08:07 Replies: 431 Views: 41,282 Posted By paulunderwood Gender populations are not 50::50. Most forumites... Gender populations are not 50::50. Most forumites here happen to be male. Some people like to identify as non-binary gender. "Dobri" is mainly a man's name. Like your guess at 168Mb for the next...
 2021-11-28, 07:50 Replies: 82 Sticky: Primo reservation thread Views: 26,502 Posted By paulunderwood Welcome back to the fold. I should be... Welcome back to the fold. I should be continuing these shortly into the new year :devil: I can do the Mersenne cofactor Ryan reserved about a year ago too. Ryan?
 2021-11-28, 07:42 Replies: 17 Views: 7,783 Posted By paulunderwood Playing the sleuth, I think I can answer this.... Playing the sleuth, I think I can answer this. Putting "Gleit kommarechnerheizgerät" in to google translate gives "Sliding comma computer heater". The German people often concatenate their written...
 Forum: Hardware 2021-11-27, 21:34 Replies: 224 Views: 38,001 Posted By paulunderwood Formidable power. I had toyed with getting such a... Formidable power. I had toyed with getting such a system. The potential noise put me off. It would draw about 1400w running flat out. One would need a garage or basement to house it. I think it is...
 Forum: Math 2021-11-27, 09:22 Replies: 9 Views: 483 Posted By paulunderwood It is not so great since (3/2)^2-2 = 1/4 which is... It is not so great since (3/2)^2-2 = 1/4 which is already known. Just as (3)^((Mp - 1)/2) == -1 mod Mp for Mersenne primes, we have (-7)^((Wq - 1)/2) == 1 mod Wq for Wagstaff PRPs. The latter can...
 Forum: Math 2021-11-26, 23:49 Replies: 9 Views: 483 Posted By paulunderwood More on the seed 3/2 for Wagstaff numbers. ... More on the seed 3/2 for Wagstaff numbers. Mod(Mod(x,W),x^2-3/2*x+1) is at the heart because S = S0 = 3/2 = x+1/x which leads to the recurrence S=S^2-2 mod W The solution for x is ( 3/2 +-...
 Forum: Math 2021-11-26, 22:38 Replies: 9 Views: 483 Posted By paulunderwood I just found this works for (2/3)^-1 ... I just found this works for (2/3)^-1 wag(q)=W=(2^q+1)/3;S0=S=Mod(3/2,W);for(i=2,q,S=S^2-2);S==S0; So maybe there is some relationship between inverse seeds for Mersenne and Wagstaff. I.e if S0...
 Forum: Miscellaneous Math 2021-11-26, 21:22 Replies: 64 Views: 20,611 Posted By paulunderwood I don't know about what you are driving at, but... I don't know about what you are driving at, but isn't a bit like "Goldbach" -- strong numerical evidence but no proof? Anyway here is an interesting youtube video on prime gaps which sounds...
 2021-11-26, 19:47 Replies: 30 Views: 5,751 Posted By paulunderwood I have done the program with a while loop rather... I have done the program with a while loop rather than a do-while loop. You can strip out the shifted functionality as it makes no difference to timings -- for a random number it does make sense but...
 Forum: Wagstaff PRP Search 2021-11-26, 15:13 Replies: 7 Views: 781 Posted By paulunderwood 4*S = (2^q+4)/3 == 1 mod W. So S = 1/4 mod W... 4*S = (2^q+4)/3 == 1 mod W. So S = 1/4 mod W Therefore S0 = 1/4 S1 = (1/4)^2 - 2 = -31/16 S2 = (-31/16)^2 - 2 = 449/256 .... S_{q-1} = X/4^2^(q-1). This will be X if W is 4-PRP -- aren't...
 Forum: Wagstaff PRP Search 2021-11-26, 05:21 Replies: 7 Views: 781 Posted By paulunderwood This looks promising. Prove it, if you can. ... This looks promising. Prove it, if you can. You might write the code as: wag(q)=W=(2^q+1)/3;S0=S=Mod((2^(q-2)+1)/3,W);for(i=2,q,S=S^2-2);S==S0;
 2021-11-26, 05:05 Replies: 30 Views: 5,751 Posted By paulunderwood Quoting the excellent GMP website documentation: ... Quoting the excellent GMP website documentation: I changed "fdiv" to "cdiv" and all is well with Bernhard's problematic example. :grin: Bernhard should think of these artifacts as a...
 Forum: Linux 2021-11-21, 17:04 Replies: 6 Views: 959 Posted By paulunderwood That's a nice graphical way of doing it, but I am... That's a nice graphical way of doing it, but I am unsure that before copying the OS you can select /dev/sdaX. I don't want the other partitions to be destroyed. It seems to be, after a firmware...
 2021-11-20, 14:01 Replies: 13 Views: 1,627 Posted By paulunderwood The row of data for 9 digits has been added. The... The row of data for 9 digits has been added. The data for 10 digits will take another month of so. I have tried to make the English simpler. So it is worth downloading the latest copy from post #1...
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