Pascal's OPN roadblock files

[Dubslow]

58789^37-1 = prp55 = 4053950016570109853137607686401867948266351783258174737 * P113

46733917^23-1 = P45 = 385588009410305972016660003487275137513789383 * P125

The latter was tested up to t39, according to the Yafu logs.

[chris2be8]

5443^59-1 done:

Tue Mar  3 13:15:14 2015  prp59 factor: 15643327990819969353366837067862736320828228961829644936601
Tue Mar  3 13:15:14 2015  prp114 factor: 223126119352093578993275856323583615920317369035639178256997814193027096383679565598632044101612047420927870099049

Chris

[chris2be8]

Reserving:
234138894262108061^12-1
5438347^31-1

Chris

[paulunderwood]

Originally Posted by chris2be8

234138894262108061^12-1
Chris

? factor(234138894262108061^4-1)

[2 4]

[3 1]

[5 1]

[13 1]

[17 1]

[97 1]

[647 1]

[19793 1]

[21997 1]

[498833 1]

[39023149043684677 1]

[106527602622299684602461833129 1]

? factor(234138894262108061^4-234138894262108061^2+1)

[853 1]

[2132125119215893 1]

[226833388169698845353509 1]

[7284932874688379053000718461 1]

? factor(234138894262108061^4+234138894262108061^2+1)

[3 1]

[7 1]

[19 1]

[199 1]

[313 1]

[1087 1]

[2053 1]

[148387 1]

[347341 1]

[1679101 1]

[5526329359153 1]

[113302621770870351937546291 1]

Of course x^12-1=(x-1)*(x+1)*(x^2+1)*(x^2+x+1)*(x^2-x+1)*(x^4-x^2+1)

[Dubslow]

(29501^43-1)/29500<188> = 28321940238536235869285220705204643422823344840276038012609317935261050798624145310443647<89> · 1910005851...69<100>

[chris2be8]

Originally Posted by chris2be8

Reserving:
234138894262108061^12-1

Chris

Of course I really meant 234138894262108061^13-1 (it's only 1 bit different).

Chris

[Dubslow]

Originally Posted by Batalov

It is elementary, Watson.
If you have to use an snfs poly of a degree higher than the "optimal degree for the input size" (which was 5 for this difficulty-190 input but we have to use 6 or 4), then 1) do indeed consider the other side, 2) the more the degree is off (e.g a 230 with an obligatory quartic), the more reason to test uneven limits and/or 3LP. Homework: check why deg-4 poly works worse that deg-6.

Even more generally, any 500 core-hour job deserves a half an hour preparation. "15 minutes could save you 15% or more" on your sieving. A larger job deserves a larger still prep. The side of sieving is just one of half a dozen parameters that one can tune. If you are not doing that, then you are missing all the fun. Trial sieve frequently to get better skills -- except for boring projects (for boring snfs projects no skills are needed).

Yafu is indeed smarter than I:

nfs: commencing nfs on c231: 135251225971675028301856314427098894013341755820007862475449892152177360830401344474492677430599143634934682310798892907998103029838576741664948681309379622324481870922894883397493363191867346935349845226880835800040189833503235012
nfs: searching for brent special forms...
nfs: input divides 751410597400064602523400427092397^7 - 1
nfs: guessing snfs difficulty 197 is roughly equal to gnfs difficulty 140

gen: ========================================================
gen: selected polynomial:
gen: ========================================================

n: 13302522452015357583701135968080036437319319663374419291243618861343524710430605294054302262936050243750561937471265036679213855126781528186354875972627728860462872611198750606338778403195447337
# 751410597400064602523400427092397^7-1, difficulty: 197.26, anorm: 7.00e+36, rnorm: 7.51e+38
# scaled difficulty: 197.26, suggest sieving algebraic side
# size = 7.867e-10, alpha = 2.428, combined = 1.413e-11, rroots = 0
type: snfs
size: 197
skew: 1.0000
c6: 1
c5: 1
c4: 1
c3: 1
c2: 1
c1: 1
c0: 1
Y1: -1
Y0: 751410597400064602523400427092397
m: 751410597400064602523400427092397
nfs: commencing algebraic side lattice sieving over range: 7060000 - 7080000
nfs: commencing algebraic side lattice sieving over range: 7000000 - 7020000
nfs: commencing algebraic side lattice sieving over range: 7040000 - 7060000
nfs: commencing algebraic side lattice sieving over range: 7020000 - 7040000

I also seem to recall reading code that can heuristically adjust large prime size/count on either side individually, so I'm just gonna go with it eh whatever, I'll try 3ALP and see if that sieves better than 2. Can't hurt to try

Edit: 2LP and 3ALP sieve within a minute of each other on a 2d7h estimate, while 3LP was a bit over 20 minutes longer. Not too much of a difference all things considered. Yafu defaulted to 2LP of course.

[chris2be8]

Reserving two more:
3253^61-1
28793^47-1

Chris

[chris2be8]

Another one done:
(13513^53-1)/13512

 r1=2701240728568321097103929745764223614404589519849075983273741 (pp61)
 r2=23311018160915059471156552798139352393690541736335168968861176725080768497383810628348554774364297894273699886767910324607417872869873219041617664941427481 (pp155)

Chris

[Dubslow]

29573^43-1 = P50 = 80693267880221853205441155003132309250521187966781 * P138

751410597400064602523400427092397^7-1 = P58 = 2551178651974343085742851505709898547795401074468355140471 * P136

29581^43-1 = P54 = 403367396549642158779520138897130627225184319665393323 * P135

I've only had one "good" split so far.

[wblipp]

(9743^61-1)/9742 = P49 * P191 by yoyo@home with B1=43e6