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2021-05-24, 22:05   #111
richs

"Rich"
Aug 2002
Benicia, California

136610 Posts

Quote:
 Originally Posted by bsquared Thanks for the report. This is due to the same bug Stargate reported and will be fixed after I'm able to re-build the project tonight.
Thanks! I'll get the revised executable when available.

 2021-05-24, 22:12 #112 BudgieJane     "Jane Sullivan" Jan 2011 Beckenham, UK 277 Posts Feedback I've just managed to factor a C190 into PRP26, PRP52 and PRP113 using YAFU 2.02. It took 5 days and 5 hours, but that's down to my awful hardware. I am pleased with this. If anyone's interested the C190 was 30^128 + 17^128. Incidentally, I'm sure I've seen something posted about this here before, but what's the largest number of decimal digits YAFU will handle?
 2021-05-25, 20:09 #113 Stargate38     "Daniel Jackson" May 2011 14285714285714285714 2A116 Posts I've run partial factorizations of larger numbers (up to 900 digits; sometimes Yafu will crash on numbers >1000 digits, but that was before I upgraded to 2.x), and sometimes I'll get a full factorization, but it's very rare. Any chance you could post the factors of 30^128+17^128 on FactorDB? It still says it's a C190: http://www.factordb.com/index.php?id...00000441930677
2021-05-26, 13:14   #114
BudgieJane

"Jane Sullivan"
Jan 2011
Beckenham, UK

277 Posts

Quote:
 Originally Posted by Stargate38 I've run partial factorizations of larger numbers (up to 900 digits; sometimes Yafu will crash on numbers >1000 digits, but that was before I upgraded to 2.x), and sometimes I'll get a full factorization, but it's very rare.
Thank you.

Quote:
 Originally Posted by Stargate38 Any chance you could post the factors of 30^128+17^128 on FactorDB? It still says it's a C190: http://www.factordb.com/index.php?id...00000441930677
Done.
How many of these Homogeneous Cunninghams should go onto FactorDB? I've got a lot of them that I've not been posting after someone complained about them a few years back.

 2021-05-26, 14:11 #115 EdH     "Ed Hall" Dec 2009 Adirondack Mtns 29·139 Posts sigma() appears to be broken Code: 05/26/21 10:01:49 v1.35-beta @ math97, System/Build Info: Using GMP-ECM 7.0.5-dev, Powered by GMP 6.2.0 detected Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz detected L1 = 32768 bytes, L2 = 8388608 bytes, CL = 64 bytes measured cpu frequency ~= 3392.250200 using 1 random witnesses for Rabin-Miller PRP checks . . . cached 664579 primes. pmax = 9999991 >> sigma(28,1) 56 >> Code: YAFU Version 2.0 Built with GCC 9 Using GMP-ECM 7.0.5-dev, Powered by GMP 6.2.0 Detected Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz Detected L1 = 32768 bytes, L2 = 8388608 bytes, CL = 64 bytes Using 1 random witness for Rabin-Miller PRP checks Cached 664579 primes; max prime is 9999991 . . . >> sigma(28,1) ans = 1 >>
2021-05-26, 15:52   #116
chris2be8

Sep 2009

2,179 Posts

Quote:
 Originally Posted by BudgieJane How many of these Homogeneous Cunninghams should go onto FactorDB? I've got a lot of them that I've not been posting after someone complained about them a few years back.
Assuming you don't have millions of them they should all go into factordb once you have fully factored them.

I think I once complained about a load of small unfactored ones being added to factordb (I am running a script to factor small number iin factordb, it went to the trouble of factoring them only to find them done when it tried to submit the result).

Chris

 2021-05-27, 12:07 #117 bsquared     "Ben" Feb 2007 67728 Posts Version 2.03 is now available with recently reported bugs fixed. Thanks Stargate38, richs, and EdH!
 2021-05-27, 13:38 #118 EdH     "Ed Hall" Dec 2009 Adirondack Mtns 29·139 Posts Great! Thanks for all your work!
 2021-05-28, 15:12 #119 richs     "Rich" Aug 2002 Benicia, California 2·683 Posts Thanks, Ben. Your efforts are most appreciated!
 2021-05-30, 12:53 #120 charybdis     Apr 2020 5×101 Posts There appears to be a bug in SNFS polynomial selection for (at least) the k*b^n+-1 and b^n+-k forms, for example: Code: $yafu "snfs(1281979*2^520+1,615852095139018818180740532155742854813285752039357209617222174313731523072704248288595303399267379211703243385678043310396893565702501281889421988426549324889)" Applying tune_info entry for LINUX64 - Intel(R) Core(TM) i5-8500 CPU @ 3.00GHz YAFU Version 2.02 Built with GCC 9 Using GMP-ECM 7.0.5-dev, Powered by GMP 6.2.1 Detected Intel(R) Core(TM) i5-8500 CPU @ 3.00GHz Detected L1 = 32768 bytes, L2 = 9437184 bytes, CL = 64 bytes Using 1 random witness for Rabin-Miller PRP checks Cached 664579 primes; max prime is 9999991 =============================================================== ======= Welcome to YAFU (Yet Another Factoring Utility) ======= ======= [email redacted] ======= ======= Type help at any time, or quit to quit ======= =============================================================== >> nfs: checking for job file - no job file found nfs: checking for poly file - no poly file found nfs: commencing nfs on c163: 4400263219768289455901391102252782697640926698321207262715052435471611732354471854022013442787765424467619673990669619452785804526944371659099920107307694926331905 nfs: searching for brent special forms... nfs: input divides 1281979*2^520 + 1 gen: ======================================================== gen: considering the following polynomials: gen: ======================================================== Error: M=1361129467683753853853498429727072845824 is not a root of f(x) % N n = 615852095139018818180740532155742854813285752039357209617222174313731523072704248288595303399267379211703243385678043310396893565702501281889421988426549324889 f(x) = + 1281979*x^4 + 0*x^3 + 0*x^2 + 0*x^1 - -1*x^0 Remainder is 615852095139018818180740532155742854813285752039357209617222174313731523072704248288595303399267379211703243385678043310396893565702501281889421988426549324887 Error: M=20282409603651670423947251286016 is not a root of f(x) % N n = 615852095139018818180740532155742854813285752039357209617222174313731523072704248288595303399267379211703243385678043310396893565702501281889421988426549324889 f(x) = + 1281979*x^5 + 0*x^4 + 0*x^3 + 0*x^2 + 0*x^1 - -1*x^0 Remainder is 615852095139018818180740532155742854813285752039357209617222174313731523072704248288595303399267379211703243385678043310396893565702501281889421988426549324887 nfs: no snfs polynomial with small coefficients found nfs: failed to find snfs polynomial! Those remainders would suggest that YAFU is getting the sign of the constant term wrong. This is 2.02 but it doesn't look like anything relevant has changed in 2.03. Also, I notice that the required ECM effort is not reduced when an SNFS special form is detected, necessitating a manual change to pretest_ratio.  2021-05-31, 21:18 #121 EdH "Ed Hall" Dec 2009 Adirondack Mtns 29·139 Posts Sorry if I'm becoming annoying, but the current "-silent" option doesn't act as before. I can (re)write my scripts around it (or use YAFU 1...), but the original YAFU performed thusly: Code: $ ./yafu "sigma(28,1)-28" -silent 28 $ which was easy to capture in a script. YAFU 2... performs in this manner: Code: $ ./yafu "sigma(28,1)-28" -silent ans = 28 \$ Although I can parse these three lines, it is easier not having to. Thanks for all your development work.

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