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 Showing results 1 to 25 of 1000 Search took 0.21 seconds. Search: Posts Made By: R. Gerbicz
 Forum: Math 2021-04-12, 23:09 Replies: 2 Views: 87 Posted By R. Gerbicz Your error is in the assumptation that mp is... Your error is in the assumptation that mp is prime by 1/log(mp) probability. The true is that it is prime by a "much" larger probability: c*log(log(mp))/log(mp) probability [what is...
 Forum: Prime Gap Searches 2021-04-05, 13:51 Replies: 18 Views: 511 Posted By R. Gerbicz For that record used only your 1st method with... For that record used only your 1st method with the following modification: collect in array/vector those res values that occur maximal times as x%p and choose randomly(!) one res value from these....
 Forum: Prime Gap Searches 2021-04-02, 23:22 Replies: 18 Views: 511 Posted By R. Gerbicz Improved solution with 6727 numbers survived the... Improved solution with 6727 numbers survived the sieve: ...
 Forum: YAFU 2021-03-24, 22:48 Replies: 62 Views: 27,616 Posted By R. Gerbicz Found these two posts from different threads: ... Found these two posts from different threads: https://www.mersenneforum.org/showpost.php?p=54147&postcount=33 https://www.mersenneforum.org/showpost.php?p=530352&postcount=23
 Forum: PrimeNet 2021-03-22, 23:06 Replies: 8 Views: 356 Posted By R. Gerbicz These were discussed multiple times. A new thing... These were discussed multiple times. A new thing to demonstrate that the shiftcount trick is actually not enough! We claim that mult(x,y,p) returns (x*y)%(2^p-1), and implement [correctly!] the...
 Forum: Hardware 2021-03-21, 17:00 Replies: 16 Views: 729 Posted By R. Gerbicz Checkout that p95 can change the blocksize, I... Checkout that p95 can change the blocksize, I don't see any advantage to fix it. Yes, that is true. I have overlooked that as I can remember gpuowl is a little tricky in this area, because it...
 Forum: Hardware 2021-03-21, 12:13 Replies: 16 Views: 729 Posted By R. Gerbicz Looks like my above formula is good, my... Looks like my above formula is good, my reasoning: we have q=(1-e)^B probability that in a single block all B iterations is good. You have 2*sqrt(B) iterations to do the in the check per block, and...
 Forum: Hardware 2021-03-19, 21:07 Replies: 16 Views: 729 Posted By R. Gerbicz Suboptimal run, with those many errors you could... Suboptimal run, with those many errors you could get a very good approx for the error rate and using that you/we could optimize the block size to lower the expected number of iterations. Check me:...
 2021-03-11, 17:14 Replies: 27 Views: 806 Posted By R. Gerbicz It is a perfect counterexample to your claim in... It is a perfect counterexample to your claim in the first post. Likely a=11 seems to be equally good just as a=3, maybe there is no other counterexample for a=11. Let me check [only the first few odd...
 2021-03-11, 16:16 Replies: 27 Views: 806 Posted By R. Gerbicz So you want to say that if a^((mp-1)/2)==-1 mod... So you want to say that if a^((mp-1)/2)==-1 mod mp for given a>2 then mp is prime. It would follow that Mp is always prime(!), just use a=-1+mp. To see a non-trivial counterexample: let a=11 and...
 Forum: Miscellaneous Math 2021-03-04, 18:03 Replies: 15 Views: 593 Posted By R. Gerbicz Destroyed? rate=0.1;year=21;(1+rate)^year ... Destroyed? rate=0.1;year=21;(1+rate)^year rate=0.03;year=3;(1-(1+rate)^(-year))/rate answer: %1 = 7.4002499442581601012110000000000000000 %2 = 2.8286113548946809221333416306177114687
 Forum: Factoring 2021-03-03, 15:21 Replies: 13 Views: 2,305 Posted By R. Gerbicz An early slide from him:... An early slide from him: https://eurocrypt2009rump.cr.yp.to/e074d37e10ad1ad227200ea7ba36cf73.pdf Forums about these claims:...
 Forum: Miscellaneous Math 2021-03-02, 20:32 Replies: 7 Views: 504 Posted By R. Gerbicz Very standard heuristic idea gives that we are... Very standard heuristic idea gives that we are expecting very few [maybe zero] composites for G=nextprime(n!)-n! [if we exclude the G<2 cases]. As you noted to find composite G we need G>n^2 so...
 Forum: Data 2021-02-24, 20:17 Replies: 558 Views: 82,765 Posted By R. Gerbicz We had already a Prp-cf test on this: ... We had already a Prp-cf test on this: https://www.mersenne.org/report_exponent/?exp_lo=82939&exp_hi=&full=1 Notice that for N=(k*2^n+c)/d we're using a Fermat test using base^d as base, then...
 Forum: Miscellaneous Math 2021-02-20, 09:53 Replies: 4 Views: 294 Posted By R. Gerbicz Repeated digit sum has a name:... Repeated digit sum has a name: https://en.wikipedia.org/wiki/Digital_root .
 Forum: Miscellaneous Math 2021-02-19, 20:18 Replies: 32 Views: 1,682 Posted By R. Gerbicz Nice. You can negate that: x=F(n-1)/(F(n-2)-1)... Nice. You can negate that: x=F(n-1)/(F(n-2)-1) mod F(n) And in general: if n=u^4+1 then for x=(u^2+1)/u: x^2==2 mod n.
 Forum: Miscellaneous Math 2021-02-19, 15:18 Replies: 32 Views: 1,682 Posted By R. Gerbicz Yes, that was my method. Yes, that was my method.
 Forum: Miscellaneous Math 2021-02-19, 10:36 Replies: 32 Views: 1,682 Posted By R. Gerbicz And with linear algebra would you need... And with linear algebra would you need primepi(100)+eps=25+eps relations ? OK, take my challenge factor my GRSA100 [G means Gerbicz], n=p*q number with 100 digits. You can use "your" method, and...
 Forum: Miscellaneous Math 2021-02-19, 08:22 Replies: 32 Views: 1,682 Posted By R. Gerbicz Yes, used those known factors, but how? I mean if... Yes, used those known factors, but how? I mean if M|N then we know only small squared residues mod M in the range of sqrt(M), but we need these residues mod N and not mod M. Ofcourse you can regard...
 Forum: Miscellaneous Math 2021-02-19, 01:00 Replies: 32 Views: 1,682 Posted By R. Gerbicz Actually it is easy, using the OP's other... Actually it is easy, using the OP's other favourite number: F12 Fermat number [which was unfactored yesterday]: N=2^4096+1;...
 Forum: Information & Answers 2021-02-15, 17:10 Replies: 26 Views: 6,979 Posted By R. Gerbicz Oh, yes that is even better what I've written,... Oh, yes that is even better what I've written, and maybe: forcing that the server wouldn't give out the same prime exponent twice per day. In this way even if you have a fully factorized mp you would...
 Forum: Information & Answers 2021-02-14, 23:39 Replies: 26 Views: 6,979 Posted By R. Gerbicz Interesting topic. Still don't see a way, my... Interesting topic. Still don't see a way, my failed approach in the prp(!) setup: The key idea is to change the base after a successful mining to a random base with say 64 bits. And then the new...
 Forum: Homework Help 2021-02-13, 21:46 Replies: 3 Views: 488 Posted By R. Gerbicz If x is composite then we know: ... If x is composite then we know: c*x/log(log(x))0 is a constant [c=0.25 is good for all x>6]. ok, not very elegant to use these, though this is still elementary. With...
 Forum: Chess 2021-01-31, 19:40 Replies: 12 Views: 1,391 Posted By R. Gerbicz Yes, forget that above we need to store also the... Yes, forget that above we need to store also the number of bits of x. Here 15 or 16 bits should be enough maybe for all games.
 Forum: Chess 2021-01-31, 15:02 Replies: 12 Views: 1,391 Posted By R. Gerbicz Even easier way if you want to encode only a... Even easier way if you want to encode only a single/few game: use a generalized number system, say in the i-th move you have only B[i] valid moves you have chosen the r[i]-th move from these. And...
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