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Old 2009-01-12, 04:27   #1
WraithX's Avatar
Mar 2006

50510 Posts
Default Lucky gmp-ecm curve...

I just found a 41 digit factor using a B1=1e6! I was hoping it might make it onto the Top list for 2009, but I see the last entry is already at 42 digits. Oh well, Just wanted to share with everyone.

Has anyone else had a lucky curve, where you found a factor that is "many" digits above what was expected?

echo "10^121-8363" | ./ecm -sigma 242376148 1000000
GMP-ECM 6.1.2 [powered by GMP 4.2.1] [ECM]
Input number is 10^121-8363 (121 digits)
Using B1=1000000, B2=1045563762, polynomial Dickson(6), sigma=242376148
Step 1 took 13469ms
Step 2 took 7797ms
********** Factor found in step 2: 57315926928065111052544509749282072073751
Found probable prime factor of 41 digits: 57315926928065111052544509749282072073751
Composite cofactor (10^121-8363)/57315926928065111052544509749282072073751 has 81 digits
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