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Old 2017-09-26, 17:44   #419
fivemack
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Default 122!+1 factorised

Code:
Tue Sep 26 13:52:55 2017  p91 factor: 4677848887236079371509112476017799095774663177393219722431791912511971735380162559376754743
Tue Sep 26 13:52:55 2017  p95 factor: 58575885673036353440267756785956285330081614442720104949735134231099056265135970148868099746681
Four hundred million thread-seconds on E5-2650v1 CPUs to sieve, 180.5 hours on four cores of an i7-4790K to solve 15.77M density-124 matrix.

Code:
Sun Sep 17 23:17:35 2017  R0: -591281735290037783396107864550988030
Sun Sep 17 23:17:35 2017  R1: 925229652860623457
Sun Sep 17 23:17:35 2017  A0: 837617633100720360598805185663419511098097609
Sun Sep 17 23:17:35 2017  A1: 58926104896555687744278064211806550519
Sun Sep 17 23:17:35 2017  A2: -2917030440222286600576256459429
Sun Sep 17 23:17:35 2017  A3: -24369367562460323330531
Sun Sep 17 23:17:35 2017  A4: 802023906814012
Sun Sep 17 23:17:35 2017  A5: 3791340
Sun Sep 17 23:17:35 2017  skew 62636602.58, size 3.020e-18, alpha -7.140, combined = 3.389e-14 rroots = 5
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Old 2017-09-26, 18:41   #420
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Nice. There are currently now only 3 factorial numbers with cofactors less than C200: 167!-1 C181, 145!-1 C185, and 169!+1 C193. Of these, I've done the most ecm on 145!-1 (t55 done, plus some of t65).
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Old 2017-09-26, 21:17   #421
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I am concentrating on Fibonacci and Lucas numbers for the next little while, but I'm inclined to put my marker down on 139!+1 C202 ... my Bayesian model suggests 20480 curves at B1=850M would suffice, which is not much more than a month on a GTX1080, and that my cluster could do the sieving inside a year.
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Old 2017-09-26, 21:46   #422
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Quote:
Originally Posted by fivemack View Post
I am concentrating on Fibonacci and Lucas numbers for the next little while, but I'm inclined to put my marker down on 139!+1 C202 ... my Bayesian model suggests 20480 curves at B1=850M would suffice, which is not much more than a month on a GTX1080, and that my cluster could do the sieving inside a year.
I've done 5326 curves with B1=850M on 139!+1. It's slow progress but better than nothing.
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Old 2017-10-02, 20:05   #423
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Quote:
Originally Posted by fivemack View Post
Code:
Tue Sep 26 13:52:55 2017  p91 factor: 4677848887236079371509112476017799095774663177393219722431791912511971735380162559376754743
Tue Sep 26 13:52:55 2017  p95 factor: 58575885673036353440267756785956285330081614442720104949735134231099056265135970148868099746681
Four hundred million thread-seconds on E5-2650v1 CPUs to sieve, 180.5 hours on four cores of an i7-4790K to solve 15.77M density-124 matrix.

Code:
Sun Sep 17 23:17:35 2017  R0: -591281735290037783396107864550988030
Sun Sep 17 23:17:35 2017  R1: 925229652860623457
Sun Sep 17 23:17:35 2017  A0: 837617633100720360598805185663419511098097609
Sun Sep 17 23:17:35 2017  A1: 58926104896555687744278064211806550519
Sun Sep 17 23:17:35 2017  A2: -2917030440222286600576256459429
Sun Sep 17 23:17:35 2017  A3: -24369367562460323330531
Sun Sep 17 23:17:35 2017  A4: 802023906814012
Sun Sep 17 23:17:35 2017  A5: 3791340
Sun Sep 17 23:17:35 2017  skew 62636602.58, size 3.020e-18, alpha -7.140, combined = 3.389e-14 rroots = 5
Approx 600 days on a modern quad assuming my maths was correct.
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Old 2017-11-26, 09:32   #424
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Nice ECM hit
Quote:
GMP-ECM 6.4.3 [configured with GMP 5.0.5, --enable-asm-redc] [ECM]
Input number is 770156643844071455967167069772237900199806497443887162285314170908852831709610947109159752027193967870457287629163037012723 (123 digits)
...
Run 6 out of 75:
Using B1=11000000, B2=35133391030, polynomial Dickson(12), sigma=218022604
Step 1 took 46614ms
Step 2 took 21198ms
********** Factor found in step 2: 114604494081175022333981193253631578034014729625655301
Found probable prime factor of 54 digits: 114604494081175022333981193253631578034014729625655301
Probable prime cofactor 6720126030123784459837155191891227842265888117630019204581218812700823 has 70 digits
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Old 2017-12-03, 19:30   #425
fivemack
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Default Silly challenge

10^x + 10^y + 3 feels as it ought to be an SNFS form, but with sufficiently perverse choice of x and y I think you can oblige the SNFS coefficients to get annoyingly large. How low a Murphy-E (that is, how hard a sieving step) can you contrive for x, y < 200?

e.g. 10^100+10^47+3 I think is best done as 100*(10^17)^6 + (10^17)^3 + 30000

10^100+10^58+3 = 10^5*(10^19)^5 + 10*(10^19)^3 + 3

10^100+10^9+3=(10^20)^5 + (10^9+3)

(sorry, this may not be an interesting silly question; 10^n + 10^(n/12) + 3 rather obliges you to use base 10^(n/6) and stick the rest into the bottom coefficient, and that's pretty bad for yield)

Last fiddled with by fivemack on 2017-12-04 at 13:14
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Old 2017-12-04, 12:30   #426
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Are any of these any better?

1000*N:
1000*(10^100+10^47+3)=1000*(10^25)^4+(10^25)^2+3000

250*N
250*(10^100+10^47+3)=4000*(5*10^24)^4+(5*10^24)^2+750

100*N:
100*(10^100+10^58+3) = 100*(10^20)^5+(10^20)^3+300
Lower coefficients but deg 7
10^100+10^58+3 = 100*(10^14)^7+100*(10^14)^4+13

TBH at this size you could even look at deg3. That's somewhat defeating the point though. Is it possible to move to a rational base?
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Old 2017-12-04, 13:02   #427
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Quote:
Originally Posted by henryzz View Post
1000*N:
1000*(10^100+10^47+3)=1000*(10^25)^4+(10^25)^2+3000

250*N
250*(10^100+10^47+3)=4000*(5*10^24)^4+(5*10^24)^2+750
These two are basically the same, and probably the best, since they have the correct degree.

Quote:
Originally Posted by henryzz View Post
100*N:
100*(10^100+10^58+3) = 100*(10^20)^5+(10^20)^3+300
Lower coefficients but deg 7
10^100+10^58+3 = 100*(10^14)^7+100*(10^14)^4+13
The degree-5 is probably the best. Deg-7 will be horrendous.
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Old 2017-12-06, 09:14   #428
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30720 curves at B1=850M completed on 139!+1, no factor found

Proceeding to polynomial selection
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Old 2017-12-06, 09:26   #429
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Quote:
Originally Posted by fivemack View Post
30720 curves at B1=850M completed on 139!+1, no factor found

Proceeding to polynomial selection
My total curves on 139!+1 are 6285 at B1=850M (including those I previously reported). I'll stop work on this number now.
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