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Old 2020-09-30, 16:03   #31
(loop (#_fork))
fivemack's Avatar
Feb 2006
Cambridge, England

18F016 Posts

The smallest 400-bit number with two 200-bit prime factors is

0x98B1A3CA31877A7140FEFFA30608FBAB17232646BEC3BAA167 * 0xD699697AC5B27CD0A75D35F9E19320D82A4F4101B550C65E97 = 2^399+198081

(about 15 curves at b1=1e6 for 2^399+{1..10^6} and then SNFS on about 800 400-bit numbers taking a median of 15740 seconds on one thread of i9/7940X)

I've got an evidence file with a prime factor of less than 200 bits for every 2^399+N which is composite and coprime to (2^23)! but am not quite sure where's best to put it

Last fiddled with by fivemack on 2020-09-30 at 16:03
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