mersenneforum.org Search Results
 Register FAQ Search Today's Posts Mark Forums Read

 Showing results 1 to 25 of 1000 Search took 0.44 seconds. Search: Posts Made By: paulunderwood
 Forum: Miscellaneous Math 2020-08-03, 19:36 Replies: 75 Views: 5,627 Posted By paulunderwood House of cards [n,b] = [79786523, 2982537] is a counterexample to the test given in post #74 where r=1. This was overlooked because of the same programming error indicated in post #75. The only thing to be lifted...
 Forum: Miscellaneous Math 2020-08-03, 14:20 Replies: 75 Views: 5,627 Posted By paulunderwood 1+1 selfridges Here is a 1+1 selfridges algorithm: Given a non-square n find b: kronecker(b,n)==1 kronecker(1-b,n)==-1 gcd(4-b,n)==1 gcd(4-2*b,n)==1
 Forum: Miscellaneous Math 2020-08-02, 09:15 Replies: 75 Views: 5,627 Posted By paulunderwood Second draft :book: :mooc:
 Forum: Proth Prime Search 2020-07-31, 22:23 Replies: 158 Views: 35,125 Posted By paulunderwood Congratulations for a top 20 prime! Congratulations for a top 20 prime!
 Forum: Programming 2020-07-31, 11:03 Replies: 53 Views: 7,965 Posted By paulunderwood Here is a gwnum program that tests... Here is a gwnum program that tests Euler+Frobenius as per https://mersenneforum.org/showpost.php?p=552286&postcount=74. :fish1:
 Forum: PARI/GP 2020-07-30, 13:56 Replies: 12 Views: 328 Posted By paulunderwood ?solve solve(X=a,b,expr): real root of... ?solve solve(X=a,b,expr): real root of expression expr (X between a and b), where expr(a)*expr(b)<=0. For logarithmic equations use pen and paper and an internet search engine.
 Forum: Miscellaneous Math 2020-07-30, 01:10 Replies: 75 Views: 5,627 Posted By paulunderwood Answer and warning Apart form the ill-formed question, writing b=s^2 (and found by trial and error) the answer is: (x*(1-s^2))^((n+1)/2) == s*(1-s^2)*kronecker(2*(1-s),n) (mod n, x^2-2*x+s^2), Warning: this...
 Forum: Linux 2020-07-29, 04:04 Replies: 13 Views: 400 Posted By paulunderwood This looks like a problem with unattended... This looks like a problem with unattended upgrades. Remove it (https://ostechnix.com/how-to-disable-unattended-upgrades-on-ubuntu/) with sudo apt remove unattended-upgrades or disable it via sudo...
 Forum: Linux 2020-07-29, 03:31 Replies: 13 Views: 400 Posted By paulunderwood This... This (https://serverfault.com/questions/884597/how-to-find-reason-for-system-reboot-or-shutdown-in-ubuntu-16-04-system) says run the command egrep -ir "(shut|reboot)" /var/log/*
 Forum: Linux 2020-07-29, 02:58 Replies: 13 Views: 400 Posted By paulunderwood Freshly installed Debian has to be coaxed into... Freshly installed Debian has to be coaxed into not suspending (https://wiki.debian.org/Suspend#Disable_suspend_and_hibernation) etc after ~20 minutes with a mask command. I wonder if your problem is...
 Forum: Miscellaneous Math 2020-07-28, 18:53 Replies: 75 Views: 5,627 Posted By paulunderwood Simplification Recap: The solutions to x^2-2^r*x+b=0 are x=2^(r-1)+-sqrt(4^(r-1)-b). Let r=1. Then the solutions are to the equation x^2-2*x+b=0 which are x=1+-sqrt(1-b) We have to have kronecker(1-b,n)==-1,...
 Forum: Miscellaneous Math 2020-07-28, 02:05 Replies: 75 Views: 5,627 Posted By paulunderwood A very short paper :book:
 Forum: Miscellaneous Math 2020-07-27, 14:23 Replies: 75 Views: 5,627 Posted By paulunderwood most general test (revised) I found some counterexamples to the above. The revised test: b%n!=0 !issquare(n) gcd(a^2-b,n)==1 gcd(a^2-2*b,n)==1 gcd(a^2-3*a,n)==1
 Forum: Miscellaneous Math 2020-07-27, 11:51 Replies: 75 Views: 5,627 Posted By paulunderwood To fool 2-PSPs and Carmichael numbers lists... To fool 2-PSPs and Carmichael numbers lists gcd(a^2-3*b,n)==1 is also required. :cool:
 Forum: Miscellaneous Math 2020-07-27, 10:15 Replies: 75 Views: 5,627 Posted By paulunderwood most general test Let x^2-a*x+b=0. The solutions are x=a/2 +- sqrt(a^2-4*b)/2. The test is: b%n!=0 !issquare(n) gcd(a^2-b,n)==1 gcd(a^2-2*b,n)==1 kronecker(a^2-4*b,n)==-1
 Forum: GpuOwl 2020-07-26, 15:06 Replies: 13 Views: 581 Posted By paulunderwood Aha! I have to do the manual results submission... Aha! I have to do the manual results submission in order to enable upload, so it seems.
 Forum: GpuOwl 2020-07-26, 11:52 Replies: 13 Views: 581 Posted By paulunderwood Uploading ability seems to be intermittent. 401... Uploading ability seems to be intermittent. 401 error. I will try later. :smile:
 Forum: Wagstaff PRP Search 2020-07-25, 15:49 Replies: 4 Views: 1,912 Posted By paulunderwood Consider x^2-2*x-1=0. This has solutions x= 1 +-... Consider x^2-2*x-1=0. This has solutions x= 1 +- sqrt(2). But 2^((W-1)/2) == -1 mod W where W=(2^p+1)/3 because kronecker(2,W) == -1. I propose the test: Mod(Mod(1,W)*x,x^2-2*x-1)^(W+1)==-1 for...
 Forum: Marin's Mersenne-aries 2020-07-25, 04:01 Replies: 36 Views: 1,098 Posted By paulunderwood Maybe v30 should be called Prime10 :grin: Maybe v30 should be called Prime10 :grin:
 Forum: GpuOwl 2020-07-25, 00:35 Replies: 13 Views: 581 Posted By paulunderwood Uploading seems to work now for the old proof... Uploading seems to work now for the old proof result format.
 Forum: PrimeNet 2020-07-24, 15:01 Replies: 45 Views: 5,224 Posted By paulunderwood Ben is doing over 10x the first time tests... Ben is doing over 10x the first time tests (https://www.mersenne.org/report_top_500_ll/) of Curtis "Chuck Norris" Cooper atm :flex:
 Forum: GpuOwl 2020-07-24, 12:05 Replies: 13 Views: 581 Posted By paulunderwood Compiled well. :smile: Edit: Uploading... Compiled well. :smile: Edit: Uploading requires the new format :tu:
 Forum: GpuOwl 2020-07-24, 10:08 Replies: 13 Views: 581 Posted By paulunderwood Two problems: 1. I can't compile the latest... Two problems: 1. I can't compile the latest gpuOwl: make gpuowl echo \"git describe --long --dirty --always\" > version.new diff -q -N version.new version.inc >/dev/null || mv version.new...
 Forum: Mlucas 2020-07-22, 21:50 Replies: 116 Views: 8,249 Posted By paulunderwood According to this page... According to this page (https://www.hardkernel.com/shop/odroid-n2-with-4gbyte-ram-2/). That is going to one hot a73, lthough it does have a optional active cooler, similar to how I set up my N2 with...
 Forum: Mlucas 2020-07-22, 11:07 Replies: 116 Views: 8,249 Posted By paulunderwood I only use the a73. The a53 is idle. It is best... I only use the a73. The a53 is idle. It is best to have two processes for 2 processors. I might fire up a double check for the a53. Running wavefront on it is too slow!
 Showing results 1 to 25 of 1000

All times are UTC. The time now is 03:19.

Tue Aug 4 03:19:42 UTC 2020 up 17 days, 23:06, 0 users, load averages: 1.16, 1.40, 1.48