20181026, 04:11  #1 
Oct 2018
1_{16} Posts 
Does NewPGen have a bug?
I was sieving k=173 from n=1M to n=2M, and I found this message by NewPGen:
p=2215115304221 divides n=1798220. However 2,215,115,304,221 is composite (that number is 8627 * 256765423), so that message should not have popped up. Why didn't NewPGen remove n=1798220 when it was at p=8627 or at p=256765423? In case anyone's wondering, I was using NewPGen version 2.82 on a Pentium 4 computer. The problem also appears on another Pentium 4 machine, so I'm pretty sure it's not a hardware problem. Thank Cristiano 
20181026, 04:31  #2  
Jun 2003
17×263 Posts 
Quote:


20181026, 06:28  #3 
Sep 2002
Database er0rr
3·1,033 Posts 
Isn't k=173 already sieved very deeply by PrimeGrid?

20181026, 12:01  #4 
Einyen
Dec 2003
Denmark
3×13×71 Posts 
Neither 8627 nor 256765423 is a factor of 173*2^17982201, so it must have been p=2215115304211 as axn pointed out.

20181026, 12:08  #5 
"Carlos Pinho"
Oct 2011
Milton Keynes, UK
11^{2}·37 Posts 

20181026, 13:26  #6 
"Mark"
Apr 2003
Between here and the
11×509 Posts 
Why are you using newpgen for this form? Use srsieve/sr1sieve. They are much, much faster than newpgen for this form.

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