Thread: 7- table
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Old 2007-07-18, 10:05   #8
fivemack
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Feb 2006
Cambridge, England

193616 Posts
Default New 7-repunit pseudoprime

(7^35201-1)/6 is a base-3 pseudoprime.

At 29749 digits it's much too big for ECPP (20562 digits took six K8/2400-years, 15071 digits took two Xeon/2600-years); 35200 looks splendidly composite, so I suppose I should start hunting cyclotomic factors.
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