Message 6769 from Yahoo.Groups.Primeform

Return-Path: <Paul.Jobling@...> X-Sender: Paul.Jobling@... X-Apparently-To: primeform@yahoogroups.com Received: (qmail 41347 invoked from network); 28 Dec 2005 11:51:34 -0000 Received: from unknown (66.218.66.218) by m25.grp.scd.yahoo.com with QMQP; 28 Dec 2005 11:51:34 -0000 Received: from unknown (HELO n2a.bullet.scd.yahoo.com) (66.94.237.36) by mta3.grp.scd.yahoo.com with SMTP; 28 Dec 2005 11:51:34 -0000 Comment: DomainKeys? See http://antispam.yahoo.com/domainkeys Received: from [66.218.69.5] by n2.bullet.scd.yahoo.com with NNFMP; 28 Dec 2005 11:49:42 -0000 Received: from [66.218.66.80] by mailer5.bullet.scd.yahoo.com with NNFMP; 28 Dec 2005 11:49:42 -0000 Date: Wed, 28 Dec 2005 11:49:41 -0000 To: primeform@yahoogroups.com Message-ID: <dotu4l+193h@...> In-Reply-To: <dorpa1+ksap@...> User-Agent: eGroups-EW/0.82 MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable X-Mailer: Yahoo Groups Message Poster X-Yahoo-Newman-Property: groups-compose X-Originating-IP: 66.94.237.36 X-eGroups-Msg-Info: 1:12:0:0 X-Yahoo-Post-IP: 213.122.46.34 From: "p_jobling" <Paul.Jobling@...> Subject: Re: Paul Jobling's record palindrome X-Yahoo-Group-Post: member; u=7262661; y=yGILDKofhAlR0OZm6PcNk0x-BAmpLF5Uoqu_WIyvMjX9NFHn X-Yahoo-Profile: p_jobling
>> what sieving program are you using (is it NewPGen) ? > I am pretty sure this is a custom siever. It is indeed (though since I used the nuts and bolts of NewPGen for the functionality, it was easiest to actually put it in the product). It is not too tricky: 10^(2n+6)+10^n*P7+1 = 0 (mod p) > P7 = -(10^(2n+6)+1).10^(-n) (mod p) (P7 a 7 digit palindrome). We can find 10^(2n+6) mod p using RTL exponentiation, and 10^(-n) by finding 10^(-1) mod p then more RTL. I couldn't find any more shortcuts though, such as any Aurifeuillian-like factorization for certain P7 values. > With my best wishes for a happy new year with many new prime > discoveries. I would second that. A question for the group: what would be top of your feasible wishlist this year? Regards, Paul.
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