Path: csiph.com!weretis.net!feeder4.news.weretis.net!feeder1.news.weretis.net!news.solani.org!.POSTED!not-for-mail From: Thomas 'PointedEars' Lahn Newsgroups: comp.lang.javascript Subject: Re: Primality sieve challenge Date: Tue, 19 Jan 2016 20:04:28 +0100 Organization: PointedEars Software (PES) Lines: 34 Message-ID: <1860806.lZUhBWmd6J@PointedEars.de> References: <5b608a56-e16b-4467-a0ce-4e30f6796920@googlegroups.com> <37264925.IaaGi9xk8D@PointedEars.de> <87ziw27kln.fsf@bsb.me.uk> <2865358.ifOrN9Bpor@PointedEars.de> <0f34c52b-ae45-49b0-8363-080d3d11d5fb@googlegroups.com> <3532030.noGN7VB15C@PointedEars.de> <06c1db3d-5ab3-4d76-bb98-b48adfbaa900@googlegroups.com> Reply-To: Thomas 'PointedEars' Lahn Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8Bit X-Trace: solani.org 1453230300 760 eJwFwYcBwDAIA7CXMrAh55Th/0+ohMvNciNoEMT2yUa7+CLXmFQZcVY/pPZ8WW20wmEcn/sDOfcR1w== (19 Jan 2016 19:05:00 GMT) X-Complaints-To: abuse@news.solani.org NNTP-Posting-Date: Tue, 19 Jan 2016 19:05:00 +0000 (UTC) User-Agent: KNode/4.14.2 X-User-ID: eJwNysEBwCAIA8CVREnAcVTI/iO09z4sGl84QYcgzenZbBjHZmRdOx41W770KoGBisJOO6HG9b+rdEM49voDS+QWEQ== Cancel-Lock: sha1:eB28dSYQ+KglzjyLeogdFUy3okM= X-NNTP-Posting-Host: eJwFwQERACAIA8BKerKNOlOgfwT/cbj5FAQDg6Hqwhb5PJFK7FleS6ejqyZc5uk7SEHwByfxEZo= Xref: csiph.com comp.lang.javascript:29357 Scott Sauyet wrote: > Thomas 'PointedEars' Lahn wrote: >> Scott Sauyet wrote: >>> Thomas 'PointedEars' Lahn wrote: >>>> Ben Bacarisse wrote: >>>>> but all those that have the form 6k + {0, 2, 3, 4} are clearly >>>>> composite. >>>> I can see why it is so for {0, 2, 4} (all multiples of 6 are divisible >>>> by 2, so are the sums when added 2 or 4), but why also for the summand >>>> 3? >>> Because 6k + 3 is divisible by 3. >> […] >>> And if it's greater than 5 it's clearly not equal to 3, so it's not >>> prime. >> I find that a specious argument at best. > > A number that is divisible by a prime, but is not actually equal to that > prime is, by definition, composite. I can't see why you consider that > specious. I find that argument specious *at best* because it does not follow that a number is not prime when it is greater than 5 and not equal to 3. Perhaps I am misunderstanding what you mean by “it”. > [explanation] Thanks, see my other followup. -- PointedEars FAQ: | SVN: Twitter: @PointedEars2 | ES Matrix: Please do not cc me. / Bitte keine Kopien per E-Mail.