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 Showing results 1 to 25 of 1000 Search took 0.18 seconds. Search: Posts Made By: R. Gerbicz
 Forum: Chess 2021-01-17, 12:50 Replies: 2 Max chess moves available in a single turn with standard rules? Views: 129 Posted By R. Gerbicz See:... See: https://chess.stackexchange.com/questions/4490/maximum-possible-movement-in-a-turn
 Forum: Puzzles 2021-01-04, 20:50 Replies: 13 An old puzzle for the new year Views: 531 Posted By R. Gerbicz We need for a given x>0 that... We need for a given x>0 that x=a+..+(a+b)=(2*a+b)*(b+1)/2 with a,b>0 So: 2*x=(2*a+b)*(b+1) Notice that 2*a+b and b+1 has different parity, hence if x is a power of two then this equation has no...
 Forum: Forum Feedback 2020-12-26, 16:25 Replies: 4 Need help Views: 370 Posted By R. Gerbicz Also this thread?? Also this thread??
 Forum: Programming 2020-12-25, 18:54 Replies: 37 Calculator that can factor and find exact roots of polynomials Views: 8,729 Posted By R. Gerbicz That is way slower than my brain, it is... That is way slower than my brain, it is irreducible with Eisenstein's criterion using p=2, ref: https://en.wikipedia.org/wiki/Eisenstein%27s_criterion
 Forum: Math 2020-12-15, 00:53 Replies: 16 Question about selection of a in the P-1 algorithm Views: 615 Posted By R. Gerbicz The reason: 2^(E*2*p)==1 mod 2^p-1. The reason: 2^(E*2*p)==1 mod 2^p-1.
 Forum: Tales From the Crypt(o) 2020-12-13, 19:55 Replies: 7 After 51 years, the Zodiac Killer's cipher has been solved by amateur codebreakers Views: 548 Posted By R. Gerbicz Probably not found, all of them looks like... Probably not found, all of them looks like gibberish, but here it is: using a wordlist of size=9027 [basically a 10k list, but deleted all words with length<4 that was not in a 4k list]. All...
 Forum: y-cruncher 2020-12-08, 12:25 Replies: 49 50 Trillion Digits of Pi Views: 25,198 Posted By R. Gerbicz False, I've written this: "if you're claiming a... False, I've written this: "if you're claiming a world record then I would choose 1 million random positions and you should give the bits for each of these positions. The check: select say 20-25...
 Forum: y-cruncher 2020-12-08, 10:59 Replies: 49 50 Trillion Digits of Pi Views: 25,198 Posted By R. Gerbicz That's why your suggested methods is just not... That's why your suggested methods is just not working (needs to repeat the whole computation), but my proposed way is using much less time. For comparison in this record size the BBP takes less than...
 Forum: y-cruncher 2020-12-07, 14:05 Replies: 49 50 Trillion Digits of Pi Views: 25,198 Posted By R. Gerbicz So you would accept any(?) hash value as a proof,... So you would accept any(?) hash value as a proof, say claiming 256T digits of Pi, and giving only sha256 as: a19a6c3a75783b6b5deee64777873ae207764837e769eedbe9b4c485d94b2986
 Forum: y-cruncher 2020-12-05, 18:08 Replies: 49 50 Trillion Digits of Pi Views: 25,198 Posted By R. Gerbicz There is no BBP type formula for Pi in base ten... There is no BBP type formula for Pi in base ten [though there could be], https://en.wikipedia.org/wiki/Bailey%E2%80%93Borwein%E2%80%93Plouffe_formula . But even giving only the last few bits would...
 Forum: Programming 2020-11-29, 00:33 Replies: 37 Calculator that can factor and find exact roots of polynomials Views: 8,729 Posted By R. Gerbicz Try x^720-1. On an older Chrome it is just... Try x^720-1. On an older Chrome it is just crashing, on Firefox after some computation it has given: "index out of bounds", the 2nd run is still computing and it is in the: "Computing LLL in matrix...
 Forum: Puzzles 2020-11-26, 20:58 Replies: 34 13x666=2020 Views: 1,470 Posted By R. Gerbicz For Q2 the optimal is 9 terms (using 4 pieces of... For Q2 the optimal is 9 terms (using 4 pieces of 13 and 5 pieces 666): 13-(666-(666+666)*(666+13*(13+13)))/666 and for Q1 the optimal is the above 8 terms. Assuming that we would use "only"...
 Forum: GpuOwl 2020-11-22, 16:04 Replies: 195 GpuOwl 7.x Views: 12,279 Posted By R. Gerbicz In that P1(5.5M) the 5.5M is the first stage... In that P1(5.5M) the 5.5M is the first stage limit in the P-1 method. The product of prime powers up to that limit has roughly 5.5*10^6/ln(2)=7934822 bits. And there was no P-1 method inside the... 2020-11-13, 18:44 Replies: 9 x!^n+/-1 or x#^n+/-1? Views: 659 Posted By R. Gerbicz Exactly. There is a not hard pattern for these... Exactly. There is a not hard pattern for these factors: if additionally you remove all lower exponents factors then for the remaining p prime factors what divides polcyclo(n,x) we have p%n=1. You...
 Forum: FermatSearch 2020-11-07, 19:53 Replies: 32 how to get F118 factor 1527888802614951*2^120+1? Views: 1,695 Posted By R. Gerbicz Actually for large n it is better to do a Proth... Actually for large n it is better to do a Proth test, which takes the same amount of time, but you could discover million+ digit prime (that is not divide any Fermat number). And if it is prime then...
 Forum: Software 2020-11-02, 21:32 Replies: 46 Sticky: LLR version 3.8.24 released. Views: 8,718 Posted By R. Gerbicz You shouldn't see such slowdown due to the... You shouldn't see such slowdown due to the checking. See what gpuowl is using L=400 or L=1000 with that the slowdown is "only" 2/L part of the total running time. p95 is using a not fixed L, changing...
 Forum: GPU Computing 2020-11-01, 19:33 Replies: 0 Better error correction Views: 990 Posted By R. Gerbicz Better error correction With a probably restarted computation the task is to compute base^(2^n) mod N, so here we can have that base is "big". As usual the standard setup, let: x[t]=base^(2^(t*L)) mod N...
 Forum: Information & Answers 2020-10-26, 00:11 Replies: 12 why is P1 no longer awarded? Views: 1,298 Posted By R. Gerbicz Not checked, but do you reward also the p-1 work... Not checked, but do you reward also the p-1 work when it is hidden in the prp test during the (new) gpuowl 7 run?
 Forum: Miscellaneous Math 2020-10-22, 11:58 Replies: 6 Primes made mostly of nines Views: 768 Posted By R. Gerbicz Combined Theorem 1 is enough from... Combined Theorem 1 is enough from https://primes.utm.edu/prove/prove3_3.html with F1=1, F2=10^8668.
 Forum: Software 2020-10-18, 22:55 Replies: 46 Sticky: LLR version 3.8.24 released. Views: 8,718 Posted By R. Gerbicz Basically in the algorithm there is "almost" only... Basically in the algorithm there is "almost" only squarings and very few multplications (at the stuff for error computation). For N=(k*b^n+c)/d using a^d as "base" with Fermat's little theorem if...
 Forum: GpuOwl 2020-10-11, 15:16 Replies: 20 GpuOwl PRP-Proof changes Views: 2,925 Posted By R. Gerbicz What processor bug you would detect with my error... What processor bug you would detect with my error check, actually it would not give any "correct or incorrect" answer because in a non-random FFT implementation it would not pass the error check with...
 Forum: Miscellaneous Math 2020-10-10, 15:59 Replies: 18 Prime Numbers Book Views: 1,720 Posted By R. Gerbicz On page 39: "The Euler Phi Function is useful... On page 39: "The Euler Phi Function is useful since for all a a^(1+φ(n)) ≡ a (mod n)." This is very false, a small counter-example is a=2, n=4.
 Forum: Math 2020-10-09, 20:12 Replies: 8 Why does a prime p divide a Fermat Number? Views: 817 Posted By R. Gerbicz Really not read, in general I know the shortest... Really not read, in general I know the shortest proofs. Another way: If 2^(2^m)==-1 mod d then for n>m taking this to the 2^(n-m)-th power: 2^(2^n)==1 mod d from this F(n)==2 mod d and the rest is...
 Forum: Math 2020-10-09, 08:52 Replies: 8 Why does a prime p divide a Fermat Number? Views: 817 Posted By R. Gerbicz I've learnt in this nice way:... I've learnt in this nice way: F(n)=2+F(0)*F(1)*F(2)*...*F(n-1), so if we have a common divisor d of F(n) and F(m), where m
 Forum: FermatSearch 2020-10-06, 22:39 Replies: 324 Sticky: New Fermat factors Views: 49,652 Posted By R. Gerbicz As I can remember pfgw is doing this (or... As I can remember pfgw is doing this (or something like that, the constant=50 is not that interesting, we'd catch all known factors if n is not small: n>50): let N=k*2^n+1 and r(u)=u^(2^(n-50)) mod...
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