20161228, 20:00  #45  
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
9,161 Posts 
Quote:
In comparison, it takes you 25 hours and 38 minutes to do a job that takes 10 minutes. That doesn't bother you? Not at all? 

20161228, 20:26  #46  
May 2007
Kansas; USA
7^{2}×11×19 Posts 
Quote:
So now I'm sad that you make fun of my old machines and software that take almost twice as long as you say it should. (lol) Anyway...a modern machine running a modern version of PFGW with some sieving done should likely take ~5 minutes. I don't think anything bothers Sweety. We can insult him all day long and he just keeps posting trivial results. Last fiddled with by gd_barnes on 20161228 at 20:28 

20161228, 22:43  #47  
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
9161_{10} Posts 
Quote:
Quote:


20161229, 00:24  #48  
May 2007
Kansas; USA
7^{2}×11×19 Posts 
Quote:
ABC ($a*10^$b$c)/9 // Sieved to 1000000000 with srsieve 269 47 +1 269 51 +1 269 84 +1 269 96 +1 269 105 +1 (etc.) LLR would not run. It runs fine without the denominator. I'm running LLR 3.8.13...not the latest version but it should be recent enough. 

20161229, 02:29  #49 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
9,161 Posts 
Code:
ABC ($a*$b^$c$d)/$e 269 10 47 +1 9 ... 
20161229, 07:29  #50 
May 2007
Kansas; USA
7^{2}×11×19 Posts 
Thanks! Not bad. About 8 mins on that same old machine with 5 other cores running, which includes about 1 minute to oversieve to 1G. If done efficiently on a modern machine...likely 3 mins.

20161229, 08:52  #51 
Romulan Interpreter
Jun 2011
Thailand
2^{2}×7×11×29 Posts 

20161229, 09:22  #52 
Jun 2003
7·683 Posts 

20161229, 10:19  #53  
May 2007
Kansas; USA
7^{2}·11·19 Posts 
Quote:
I did not actually sieve ($a*10^$b$c)/9. I sieved $a*10^$b$c accomplishing exactly what axn said with p 4 P 1e9. After the sieving was done I then added the parens and denominator. Btw, this was a technique that I learned from Serge less than a week ago...one that I was not aware of because I've never searched repeatdigit type forms. A note about this: In this case the sieving still leaves terms with factors of 3^q after dividing by 9. When running PFGW I get around this by trial factoring to 1% with the f1 switch so it doesn't do a full primality test. It generally takes less than 1/10th of a second to trial factor to 1%. This begs a question: Does LLR look for teeny factors before doing a primality test? I could not tell with the short test that I ran on it here. If not I may stick with PFGW because it can quickly get rid of very small factors that are left when sieving a form with a denominator like this. Last fiddled with by gd_barnes on 20161229 at 10:21 

20161229, 10:43  #54 
Romulan Interpreter
Jun 2011
Thailand
2^{2}·7·11·29 Posts 
Yes, I did exactly the same in the other thread of sweety, I just created a folder (called bp and copied his bases there, in a vector), filled it with sr_bxxx.pfgw files using pari:
Code:
gp> \r bp\bases gp > (16:13:53) gp > v %1 = [184, 185, 200, 210, 269, 281, 306, 311, 326, 331, 371, 380, 384, 385, 394, 396, 452, 465, 485, 511, 522, 570, 574, 598, 601, 629, 631, 632, 636, 640, 649, 670, 684, 691, 693, 711, 713, 731, 752, 759, 771, 795, 820, 861, 866, 872, 881, 932, 938, 948, 951, 956, 963, 996, 1005, 1015] gp > for(i=1,#v,write("BP\\nrep_b"v[i]".pfgw","ABC $a*"v[i]"^$b$c // Sieved to "nextprime(v[i])" with srsieve");forprime(p=3,10^4,write("BP\\nrep_b"v[i]".pfgw","1 "p" 1"))) time = 1min, 4,259 ms. Code:
ABC $a*636^$b$c // Sieved to 641 with srsieve 1 3 1 1 5 1 1 7 1 1 11 1 1 13 1 1 17 1 1 19 1 1 23 1 ...etc... Code:
for %p in (nrep_b*.pfgw) do srsieve S 2 m 1e8 w "%p" Then a perl command will replace all headers: Code:
for %p in (sr_*.pfgw) do perl i.bak p e "s/ABC \$a\*(\d*)\^\$b\$c/ABC (\$a*\1^\$b\$c)\/(\11)/g;" %p And of course, you will want pfgw to stop when a prime is found, therefore Code:
for %p in (*.pfgw) do perl i.bak p e "s/Sieved to \d* with srsieve/{number_primes,\$a,1}/g;" %p Code:
ABC ($a*210^$b$c)/(2101) // {number_primes,$a,1} 1 7 1 1 11 1 1 17 1 1 31 1 1 103 1 1 107 1 1 157 1 1 173 1 1 227 1 1 257 1 1 269 1 1 331 1 1 347 1 1 353 1 1 383 1 1 397 1 ...etc... Thanks anyhow... 
20161229, 11:19  #55  
May 2007
Kansas; USA
7^{2}·11·19 Posts 
Quote:
For c=1 or +1 forms, you can use sr1sieve but it will only sieve where the factors are greater than the base so you'd have to figure a way to remove smaller factors or just do like I did and run PFGW with factoring set to 1% with f1. Also if you are sieving multiple k's at once, which I am frequently doing on some of these conjectures, you have to sieve them one k at a time...not a great solution. Would someone want to get ahold of Mark (rogue) and see if he can remove the error check from srsieve and sr2sieve where it says all terms are even? That becomes a major issue when sieving near repeat digit forms for odd bases. Last fiddled with by gd_barnes on 20161229 at 11:28 

Thread Tools  
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Semiprime and nalmost prime candidate for the k's with algebra for the Sierpinski/Riesel problem  sweety439  sweety439  11  20200923 01:42 
The reverse Sierpinski/Riesel problem  sweety439  sweety439  20  20200703 17:22 
The dual Sierpinski/Riesel problem  sweety439  sweety439  12  20171201 21:56 
Sierpinski/ Riesel bases 6 to 18  robert44444uk  Conjectures 'R Us  139  20071217 05:17 
Sierpinski/Riesel Base 10  rogue  Conjectures 'R Us  11  20071217 05:08 