[CODE]598303^37-1 = 141564506618597953495404322578758873 * 173425382715900890478296318934217175388753709373685646269492132615005032816072482289330396161230911051852245406229724365723342162440733310274475448137984220934029716303[/CODE]

[CODE]9341^71-1 = 536321054561868323964339088560393553 * P243[/CODE]

[CODE]3256411^47-1 = 123990551845517800255308540638002993 * P265[/CODE]

[CODE]7123981^31-1 = 43768759531924424825804343483003280027079 * P165[/CODE]

The Brent tables numbers are getting a bit slow now, so I'll take a break doing some easier numbers from i_51_2000_101.txt (ECM first, then SNFS if necessary).

Reserving:
5336717^31-1
86353^43-1

Chris

86353^43-1 won't need SNFS:
[code]
Resuming ECM residue saved by chris@4core with GMP-ECM 7.0-dev on Wed Nov 12 17:43:04 2014
Input number is 217299428303605750964143552796283167605200189138133468679725819860114113284236626937891491226949996388687364085089660351113758620972097016957505118361336117843690313385542307 (174 digits)
Using B1=11000000-11000000, B2=35133391030, polynomial Dickson(12), sigma=3:1015838297
Step 1 took 0ms
Step 2 took 9880ms
********** Factor found in step 2: 1637372497455859450293267396543566542531415101042697
Found probable prime factor of 52 digits: 1637372497455859450293267396543566542531415101042697
Probable prime cofactor 132712274477093288121747769682453224834821397665155641925536387218142707430499259969666227538455978469807950639694262317131 has 123 digits
[/code]
So reserving 2 more for ECM, then SNFS if necessary:
128493601339^17-1
3234152111453204401^13-1

Chris

3234152111453204401^13-1 is partly factored: [code]
********** Factor found in step 2: 1652853993138597196148058279397800605185523
Found probable prime factor of 43 digits: 1652853993138597196148058279397800605185523
Composite cofactor 935095082010579037215732687663189797754745332333490467692099728082350935058700921649503756074918673994545632848959840194 336432094815758798024873569494141367 has 156 digits
[/code]
@Pascal, is it worth factoring the cofactor?

And reserving:
6115909044841454629^13-1

Chris

Thank you for handling these hard and wanted composites.
Yes, it is worth factoring the cofactor.
Would GNFS be faster than SNFS now ?
If not, how much running time do we gain thanks to this P43 ?

SNFS is probably still faster, so I'll finish ECM and do it with SNFS if necessary.

The factor will speed up ECM on the remainder, but won't speed up SNFS significantly.

Chris

(128493601339^17-1)/128493601338 is done: [code]
prp65 factor: 34452638008244778981611333120697531502847222390102198059245165043
prp114 factor: 160280814865071785713452537694471065748660900049568848854977810227742276800252185006681533636600380338627173664667
[/code]
Now sieving (5336717^31-1)/42350787022542390712689528236.

Chris

(5336717^31-1)/42350787022542390712689528236 is done: [code]
prp63 factor: 265757700716518315850245798632257963583805397294027009361810899
prp118 factor: 3119981568449506273767247469134777989749255822139409689159653216937820237303657893389473330479238708807367772544854913
[/code]
And reserving (7176374761323733117^13-1)/13488856228255048616579328765896916.

Chris