An81

 Subject: An81
    Date: Mon, 09 Nov 1998 10:04:40 +0000
    From: Allan MacLeod <MACL-MS0@wpmail.paisley.ac.uk>
      To: kc2h-msm@asahi-net.or.jp


Hello,

Been quiet lately but the following finishes off An81 = 81! - 80! + 79! - ...

Allan MacLeod


Input number is

5045022512911997564316467087038085892320957748805672116448225914602148463851674771 (82 digits)

Using B1=3000000, B2=300000000, polynomial x^30, sigma=1545001597
Step 1 took 595604ms for 39102834 muls, 3 gcdexts
Step 2 took 283132ms for 16480797 muls, 29004 gcdexts

********** Factor found in step 2: 197602347379409189701162020778649753

Found probable prime factor of 36 digits: 197602347379409189701162020778649753

Probable prime cofactor 25531187153486747474225814373437582626046250507 has 47 digits

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