So I call the stage at which the nfs.dat.p file is filled and the best poly is searched

Ah, so by preNFS you really mean the first stage of NFS. I suppose if we're being really strict about the meaning of the word "sieve" then polynomial selection is pre-NFS and postprocessing is post-NFS, but most people use NFS to refer to the whole algorithm rather than just the sieving stage.

I think going straight to GNFS after t50 at this size is suboptimal, but of course everyone's free to do what they want. If you have the resources to do the GNFS yourself, then you also have the resources to do the optimal amount of ECM.

[QUOTE=charybdis;583777]I think going straight to GNFS after t50 at this size is suboptimal[/QUOTE]This is not I started with the GNFS stage, but yafu itself after the completion of the t50 stage :smile:

So you ran t50 and then called yafu factor(), which presumably ran at least another t50?

I ran yafu -work 45 and after completing this stage automatically started pre-NFS stage for c168 and c169

You can tune how much ecm yafu will do, by using a "pretest_ratio=..." in yafu.ini file. I usually go with 0.334 (33.4%, which means, for a C168, at least a t55 will be done, and this way have a large chance to avoid a 3-way split).

Will the data generated here be used in the paper that is currently published at arxiv or will it be part of a new publication? Do you know when it will be submitted?

The C212/SNFS215 for (13,2) factors as:

[CODE]p68 factor: 65470839132891587378451398003085663493468996034812587842969753001001
p144 factor: 272999581728907243481927568287887505420486663480088950983800638257617799930179269423084728938601529213529914520447747676995095997912408303807661[/CODE]

[QUOTE=LaurV;583806]You can tune how much ecm yafu will do, by using a "pretest_ratio=..." in yafu.ini file. I usually go with 0.334 (33.4%, which means, for a C168, at least a t55 will be done, and this way have a large chance to avoid a 3-way split).[/QUOTE]Can you attach your yafu.ini?

In factor.log I see for example
[QUOTE]07/27/21 18:48:38 v1.34.5 @ UUNP-HV05N4, Starting factorization of 3247903177530905810688738828962481204542302302414955042770879837334793211816425127548527769179079565260917709105074137909390860953109380133800537359422487798480789987383771707902131083201
07/27/21 18:48:38 v1.34.5 @ UUNP-HV05N4, using pretesting plan: custom
07/27/21 18:48:38 v1.34.5 @ UUNP-HV05N4, custom pretest ratio is: 0.3340
07/27/21 18:48:38 v1.34.5 @ UUNP-HV05N4, no tune info: using qs/gnfs crossover of 95 digits
07/27/21 18:48:38 v1.34.5 @ UUNP-HV05N4, input indicated to have been pretested to t45.00
07/27/21 18:48:38 v1.34.5 @ UUNP-HV05N4, ****************************
07/27/21 18:48:38 v1.34.5 @ UUNP-HV05N4, rho: x^2 + 3, starting 1000 iterations on C187
07/27/21 18:48:38 v1.34.5 @ UUNP-HV05N4, rho: x^2 + 2, starting 1000 iterations on C187
07/27/21 18:48:38 v1.34.5 @ UUNP-HV05N4, rho: x^2 + 1, starting 1000 iterations on C187
07/27/21 18:48:38 v1.34.5 @ UUNP-HV05N4, current ECM pretesting depth: 45.67
07/27/21 18:48:38 v1.34.5 @ UUNP-HV05N4, scheduled 7553 curves at B1=43000000 toward target pretesting depth of [B][COLOR="Blue"]62.46[/COLOR][/B]
07/29/21 06:31:17 v1.34.5 @ UUNP-HV05N4, Finished 7560 curves using Lenstra ECM method on C187 input, B1=43M, B2=gmp-ecm default
07/29/21 06:31:17 v1.34.5 @ UUNP-HV05N4, final ECM pretested depth: [B][COLOR="Red"]50.85[/COLOR][/B]
07/29/21 06:31:17 v1.34.5 @ UUNP-HV05N4, scheduler: switching to sieve method
07/29/21 06:31:17 v1.34.5 @ UUNP-HV05N4, nfs: commencing nfs on c187[/QUOTE]I don't know why yafu skip at least B1=110M stage

If I'm reading the table correctly, the following are available for GNFS:

line 123 (9, -7) c168
line 166 (10, 10) c169
line 180 (2, 11) c163
line 183 (5, 11) c162

You may book all available of the four to me.

[QUOTE=EdH;584287]line 180 (2, 11) c163
line 183 (5, 11) c162
[/QUOTE]I will take soon please

c168 and c169 are free to book