fun with snfs

[smh]

Originally Posted by Anonymous

Whew. Looks tricky. I think I'll stick with the msieve number field sieve for now, though I'll keep your instructions in mind in case I try it out later--thanks!

The NFS part of msieve figure out this special (SNFS) poly for you, instead it will look for a general (GNFS) poly.

[michaf]

Originally Posted by xilman

Correction: making errors, thinking about the error messages and attempting to work out what went wrong before even thinking of asking for assistance.

If you can show you've made an honest attempt to correct your errors and are still stuck a number of people here will attempt to help you, even (especially) those who don't suffer fools gladly.

Paul

Quite true Paul :)

And to be frank, a lot of people here are very willfull to help. I just wish every community is as accessible as this one is.

PS Factored my last one with a p57*p77, penultimate factor is growing larger every time :>

[konrad127123]

Unreserving 322498*5^163-1. I've tried running ggnfs with a couple of versions and a couple of different polynomials and it's gone wrong 3 times now, usually with an error that "the rational square root is broken" when it gets to the sqrt step. I may be doing something stupid, or it might be a case of my laptop overheating.

[konrad127123]

Had a go at 177742*5^165-1 instead and that seemed to work:

N=380050036080965630829048986195550953683496579090905252538520554985258860197067619368649360467
3160007223486900329589843749
( 121 digits)
SNFS difficulty: 120 digits.
Divisors found:
r1=29396205787255986672168995722713663306388458318564899288057 (pp59)
r2=129285404664613935599483200883436197386635648913480251814428557 (pp63)

Reserving 146756*5^172-1

[michaf]

Done:

Number: 313126_5_183m1
N=25540531085581324886883594415688321374081034493401290240418384984442657008597905904817457157715554494359366799471899867057800292968749
( 134 digits)
SNFS difficulty: 134 digits.
Divisors found:
r1=316209438384459371703517965639323114163258463 (pp45)
r2=80770932126726031085558585897179567718770376875856339588019641769577892494502998491700723 (pp89)

Will try 322498*5^163-1, maybe I'll get lucky :)
(What params did you use in the .poly file?)

A nice p59 you got too, konrad :)

Edit: did you upload the factors in the database?

[konrad127123]

m: 116415321826934814453125
c5: 322498
c4: 0
c3: 0
c2: 0
c1: 0
c0: -25
skew: 2
lss: 2
knowndiv: 25
with GGNFS-0.77.1-20060722-athlon-xp
One of the sqrt's did run without any error for the above after some fiddling, but unfortunately it only found the trivial factorisation.

m: 23283064365386962890625
c5: 40312250
c0: -1
skew: 3
with GGNFS-0.77.1-20060722-athlon-xp

Then I read up on what skew was meant to be set to, so I did:

m: 116415321826934814453125
c5: 322498
c0: -25
skew: 0.15062
with GGNFS-0.77.1-20060513-athlon-xp

From memory, skew only really affects sieving speed. Is this correct?

Edit: did you upload the factors in the database?

Have done so now.

[michaf]

Either I was very lucky, or you weren't :)

I got a result on my first dependency.

Number: 322498_5_163m1
N=275827607512100131676489833466693952945325876300837758398505253550958157094741621251365870648442069068551063537597656249
( 120 digits)
SNFS difficulty: 120 digits.
Divisors found:
r1=20839135792389150753974524131155300566552072589 (pp47)
r2=13236038685099294123480006650135604472473690755587499793585978943581150941 (pp74)

[konrad127123]

Well done either way.
name: 146756_5_172-1
N=245152661121431415153125356108301796629626895835435329198813811624682164347942064323154776062096971145365387201309204101562499
( 126 digits)
SNFS difficulty: 127 digits.
Divisors found:
r1=4838678627686638179195289290160326568505738672993324848811 (pp58)
r2=50665208414272880516104417701926233625638884214440261747805170851209 (pp68)
Version: GGNFS-0.77.1-20060513-athlon-xp

Reserving: 51208*5^176+1

[konrad127123]

Number: 51208_5_176+1
N=53463646591562951034204918519489485957175235092351302236419880897870974065495691955780810378229261914384551346302032470703125001
( 128 digits)
SNFS difficulty: 130 digits.
Divisors found:
r1=19402784913081550045317357121614158885432623 (pp44)
r2=2755462518966400034375979148363156774563969220661322623817680343890163465973325231687 (pp85)
Version: GGNFS-0.77.1-20060513-athlon-xp
Total time: 8.43 hours.
I had a load of the same errors again, but the 24th dependence worked.

Reserving: 71098*5^176+1

[michaf]

Number: 322498_5_163m1
N=275827607512100131676489833466693952945325876300837758398505253550958157094741621251365870648442069068551063537597656249
( 120 digits)
SNFS difficulty: 120 digits.
Divisors found:
r1=20839135792389150753974524131155300566552072589 (pp47)
r2=13236038685099294123480006650135604472473690755587499793585978943581150941 (pp74)

reserving 24032*5^181+1

[konrad127123]

Number: 71098*5^176+1
N=74229775530521455488007758492787522898438620227229981378006965553757821319102732125294955012329012333793798461556434631347656251 ( 128 digits)
SNFS difficulty: 130 digits.
Divisors found:
r1=35735478324419980383115226382708020762773727819 (pp47)
r2=2077201118077556133697217721703951777357478778994027059921856535664491604793560529 (pp82)
Version: GGNFS-0.77.1-20060513-athlon-xp

Reserving 53546*5^200-1