I have completed the search for Repunits from 86453 up to 200,000. No new
repunits have been found, other than the previously announced PRP R(109297). The
search took about 25 days using the equivalent of 7 computers of 3.0 GHz. I
estimate that searching from 200,000 to 300,000 would take about twice this
effort.
Although I was disappointed that no additional repunits were found, I am
thoroughly impressed that the response to finding R(109297) seems to have been
to reawaken interest in proving R(49081) truly prime. Good luck to everyone
involved.
Harvey Dubner
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I have completed the search for Repunits from 86453 up to 200,000. No new repunits have been found, other than the previously announced PRP R(109297). The...
Harvey, are you (or somebody else) currently running a search on a repunit in the interval 200,000-300,000? If not, can I reserve this interval? If yes, can I...
My son and I decided to continue Harvey's search for a repunit in the interval n=200,000-300,000. As a first step we ran a trial division of repunits by...
(10^270343-1)/9 is 3-PRP! (9917.2995s+0.0513s) Already sent to http://ourworld.compuserve.com/homepages/hlifchitz/Renaud.html. We'll report search details...
... Well done. I hope you have tested it with other bases than 3. A fermat+lucas would push it towards certainly being prime. The controversy over who...
... C:\Users\Jens>pfgw -b7 -q"(10^270343-1)/9" PFGW Version 1.2.0 for Windows [FFT v23.8] (10^270343-1)/9 is 7-PRP! (6019.0176s+0.0153s) Congratulations! ... ...
Some update: 1) The PRP repunit is already listed on PRP Top (http://ourworld.compuserve.com/homepages/hlifchitz/Renaud.html) and is currently holding position...
We completed the search for PRP repunits in the range of exponents 200,000-300,000 and found no PRP repunits other than R(270343). We are going to continue the...
We completed the search for PRP repunits in the range of exponents 300,000-400,000 and found no PRPs. We are going to continue the search in the range...
can anyone help me to determine for which n's this is true. (2^(n-1)-1) is divisible by n ie mod((2^(n-1)-1 <2@%5E(n-1)-1>),n)=0 ... -- mohan srinivasan ...
... It is true for all n=prime or n is speudo prime to base 2 or all carmichael numbers like 561,1729,...41041....,... best Norman Heute schon einen Blick in...
I need (a lot of) help proving the following assumption: None of the prime factors of the repunit R(p)=(10^p-1)/9, where p is prime, will have a form...
... Let us reason together... Suppose the prime q divide (10^p-1)/9. It is clearly odd and (because p is prime) is not 3. Now focus on q dividing 10^p-1. ...
Can somebody please point out an existing fast siever to sieve repunit numbers R(p)=(10^p-1)/9 in the range of p=400,000-600,000? Thanks in advance, Max...
I presume this was meant for the whole group. ... What kind of sieving tech are you using. I presume it would fall to a SPH-style dlog pretty well. Phil...
... Hi, Phil; Unfortunately, I don't know exactly what you mean by "SPH-style dlog". I would appreciate if you reference me to some existing projects or...
I don't know how useful the following link ( I'm thinking particularly mpptf16.c ) would be in porting your code to GMP/C - but you're welcome to browse/borrow...
... at least for the purposes of your nice repunit prime search (and using GMP) - pls note the factorization algorithm presented there is proprietary, and...
We continue the search for the next PRP repunit. All exponents up to 700,000 were tested, no new PRP repunits were found. (The last one was R(270343) uncovered...
Due to release of PFGW 3.2.2, our project accelerated significantly (~5-8 times). Special thanks to Mark Rodenkirch, Steven Harvey, George Woltman, Jim...
Posted by: "mvoznyy0526 ... Don't worry, I was jibbering. (However, I meant Silver-Pohlig-Hellman. Discrete logarithms. However, as your exponents are so high,...
... I've found my old code... With a tiny bit of hand tweaking, my sieve-generator turned this: -- 8< -- repunit.abc2 --- ABC2 10^$a-1 // {$a} a: primes from...
Exponents up to 850,000 are tested, no new PRP repunits so far. Current status: http://home.oise.utoronto.ca/~mvoznyy/repunit.htm Anyone willing to join...
... I have tried 5 exponents and all of them had a 16 digits prime (or semi-prime) factor. Why is it? C:\Users\***>repunit.exe -$b=862777 -$c=862777 \\ Hard...
... Unfortunately, what you see is not a factor, it says NO prime less or equal to 1725554022432203 divides a=862777 [actually meaning that no small factors of...
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