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 Showing results 1 to 25 of 1000 Search took 0.20 seconds. Search: Posts Made By: R. Gerbicz
 Forum: Math 2021-05-15, 20:55 Replies: 2 Views: 253 Posted By R. Gerbicz Multiple (prp) test at once? When you are loading from a precomputed cos/sin table at fft or compute these in-fly then you could reuse these values. Basically hide/halve this computation cost [or just the cost of load] if you'd...
 Forum: Lounge 2021-05-14, 23:50 Replies: 20 Views: 638 Posted By R. Gerbicz That is true. For any N if you consider the b... That is true. For any N if you consider the b bases for that N is a Fermat pseudoprime then these bases form a group in Z_N. For Mersenne numbers this means that 2^n is such a base, because mp is a...
 Forum: Lounge 2021-05-04, 08:36 Replies: 40 Views: 2,859 Posted By R. Gerbicz Thought that it is puzzle similar to: ... Thought that it is puzzle similar to: https://www.mersenneforum.org/showthread.php?t=4756
 Forum: Data 2021-05-03, 21:56 Replies: 23 Views: 1,151 Posted By R. Gerbicz Doesn't worth it, the best candidates: ?... Doesn't worth it, the best candidates: ? polcyclo(3,q) %23 = q^2 + q + 1 ? polcyclo(4,q) %24 = q^2 + 1 ? polcyclo(6,q) %25 = q^2 - q + 1 It is still doesn't divisible by p and you have...
 Forum: Software 2021-04-28, 11:09 Replies: 291 Sticky: Prime95 v30.4/30.5/30.6 Views: 23,680 Posted By R. Gerbicz Exactly, add to that there is no error check in... Exactly, add to that there is no error check in P-1. You could get a partial error check in stage one if you are doing a mixed prp/pm1 test, what gpuowl is doing. I could be wrong but you could also...
 Forum: Software 2021-04-27, 13:57 Replies: 291 Sticky: Prime95 v30.4/30.5/30.6 Views: 23,680 Posted By R. Gerbicz This is still doesn't find q in the first test. ... This is still doesn't find q in the first test. More greedy run, try: Pplus1=N/A,1,2,86743,-1,86742,2000000,1,40 Pplus1=N/A,1,2,86743,-1,86743,2000000,1,40 Only the 2nd one finds the...
 Forum: GMP-ECM 2021-04-25, 19:48 Replies: 6 Views: 816 Posted By R. Gerbicz There is a neat trap here, how you... There is a neat trap here, how you should/shouldn't choose the seeds, if we remain at Wikipedia's writing: would you choose these starting values: D=3; D=77; and then D=51975 after two failures?...
 Forum: Software 2021-04-24, 23:29 Replies: 291 Sticky: Prime95 v30.4/30.5/30.6 Views: 23,680 Posted By R. Gerbicz Have you included p as a factor in the p+1 (!!)... Have you included p as a factor in the p+1 (!!) method? Looks like not... If really not then you will find no p-1 factors where p>B1 (unless with some luck), and all other factors except at most one...
 2021-04-21, 20:05 Replies: 60 Views: 3,179 Posted By R. Gerbicz Much less extra cost, say you want a^(b^n) mod N... Much less extra cost, say you want a^(b^n) mod N using error checking, then choose e>0 and set a larger new base: B=b^e, for simplicity assume that e divides n, then a^(b^n)=a^(B^(n/e)) and you...
 Forum: Science & Technology 2021-04-19, 10:29 Replies: 205 Sticky: Poll: COVID vaccination wavefront Views: 11,372 Posted By R. Gerbicz Today got the first dose of AstraZeneca. Need... Today got the first dose of AstraZeneca. Need 12 weeks for the 2nd dose.
 Forum: Math 2021-04-15, 13:59 Replies: 10 Views: 5,860 Posted By R. Gerbicz Yes, c is irrational, but not algebraic, so you... Yes, c is irrational, but not algebraic, so you can't apply https://en.wikipedia.org/wiki/Roth%27s_theorem . Quite a known constant, so there could be proven theorem on good/best approx for c.
 Forum: Math 2021-04-13, 15:59 Replies: 10 Views: 5,860 Posted By R. Gerbicz You need a greater precision, roughly 16 digits... You need a greater precision, roughly 16 digits to get the correct answer for all p<10^8. Real example using Pari-Gp: ? n=181605302766736484827; ? \p realprecision = 38 significant digits ? ...
 Forum: Math 2021-04-13, 12:58 Replies: 4 Views: 290 Posted By R. Gerbicz I've written a quite different formula. At least... I've written a quite different formula. At least one PRP/LL test has performed on each prime for p<10^8. Lets check out what your original formula says about the number of Mersenne primes for p in...
 Forum: Math 2021-04-12, 23:09 Replies: 4 Views: 290 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: 37 Views: 1,930 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: 37 Views: 1,930 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: 31,473 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: 565 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: 899 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: 899 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: 899 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: 1,009 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: 1,009 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: 839 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: 2,942 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:...
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