20201204, 18:49  #804 
Feb 2012
Paris, France
7×23 Posts 
Let n be a prime number with 500 < n < 1000.
I'm planning on doing some ECM on the numbers 17^{n}1. For n=503, I did 7100@3e8 back in 2014/2015. For n>503, I'll begin with a t35. I found three factors: P33 for 17^5211 P32 for 17^5231 P29 for 17^9291 Note: exponents 563, 577 and 683 are excluded from this effort for the moment because Ryan did some effort on them (maybe a t50 since a 49 digits factor has been found for 17^5771) since they are in mwrb2100.txt. Last fiddled with by YuL on 20201204 at 18:57 Reason: Added a note and the factor found while I was writting the post 
20201205, 17:39  #805 
Oct 2007
Manchester, UK
53D_{16} Posts 

20201205, 23:10  #806  
Feb 2012
Paris, France
7×23 Posts 
Quote:
Thanks, I used to do that... Now I just run a GMPECM linked with GWNUM and it does the job :) Code:
GMPECM 7.0.4 [configured with GMP 6.1.2, GWNUM 29.8, enableasmredc] [ECM] Tuned for x86_64/k8/params.h Due to incompatible licenses, this binary file must not be distributed. Input number is (17^5091)/(2^4*1019*10181*27487*91621) (609 digits) Found number: 1*17^509 + 1 [Sat Dec 5 22:00:48 2020] Using mpz_mod Using B1=3000000, B2=4592487916, polynomial Dickson(6), sigma=0:16358333240206248675 dF=14400, k=2, d=150150, d2=17, i0=3 Expected number of curves to find a factor of n digits: 35 40 45 50 55 60 65 70 75 80 336 2462 21289 210320 2370354 3e+07 4.2e+08 6.4e+09 1.2e+11 9.6e+15 Using gwnum_ecmStage1(1, 17, 509, 1, 3000000, 1) Step 1 took 23068ms Estimated memory usage: 194.24MB Initializing tables of differences for F took 68ms Computing roots of F took 1876ms Building F from its roots took 2316ms Computing 1/F took 1048ms Initializing table of differences for G took 116ms Computing roots of G took 1640ms Building G from its roots took 2380ms Computing roots of G took 1844ms Building G from its roots took 2340ms Computing G * H took 692ms Reducing G * H mod F took 912ms Computing polyeval(F,G) took 4648ms Computing product of all F(g_i) took 36ms Step 2 took 19972ms ********** Factor found in step 2: 10880130373003275175614033001151500697 Found prime factor of 38 digits: 10880130373003275175614033001151500697 Composite cofactor ((17^5091)/(2^4*1019*10181*27487*91621))/10880130373003275175614033001151500697 has 572 digits 

20201206, 02:50  #807  
Oct 2007
Manchester, UK
3^{2}·149 Posts 
Quote:
I'm not sure why it says this: Quote:
Quote:
This code exists in ECM, so presumably it CAN be GPL compliant? Code:
#ifdef HAVE_GWNUM #ifdef gwnum_is_gpl if (! gwnum_is_gpl ()) #endif printf ("Due to incompatible licenses, this binary file must not " "be distributed.\n"); 

20201206, 15:14  #808  
Jun 2012
Boulder, CO
2·7·19 Posts 
Quote:
Code:
$ wget http://www.mersenne.org/ftp_root/gimps/p95v303b6.source.zip $ unzip p95v303b6.source.zip $ make f make64 j 16 Code:
$ ./configure withgwnum=$HOME/p95/gwnum $ make j 16 Last fiddled with by ryanp on 20201206 at 15:14 Reason: typo 

20201206, 15:28  #809  
Just call me Henry
"David"
Sep 2007
Cambridge (GMT/BST)
1011010111110_{2} Posts 
Quote:


20201206, 16:03  #810 
Feb 2012
Paris, France
161_{10} Posts 

20201208, 15:35  #811 
Jun 2012
Boulder, CO
2×7×19 Posts 
FWIW, updated list of factors found so far: https://cs.stanford.edu/~rpropper/opn.txt

20201209, 11:04  #812  
Sep 2008
Kansas
2·31·53 Posts 
Quote:


20201209, 11:08  #813 
"Oliver"
Sep 2017
Porta Westfalica, DE
439 Posts 
Working fine yesterday and currently for me.
Chrome Canary 89.0.4349.2. Windows 10, v2004. Accessed from Germany. 
20201209, 16:03  #814  
Feb 2012
Paris, France
161_{10} Posts 
Quote:
Factors found so far: 17 509 10880130373003275175614033001151500697 17 521 507732028088571194591510571526693 17 523 89163041550752855557680359884199 17 541 210851698687146481442232546078496897 17 541 902304286550029874166103436203835437 17 911 1732550124080428168413011275808287 17 929 24635452104352854844270989359 17 967 34714203016693178317175265507286452661453 17 997 247157806053731011193258357444587433 

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