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From: bs@faron.UUCP (Robert D. Silverman)
Newsgroups: net.math
Subject: Palindromic Primes
Message-ID: <162@faron.UUCP>
Date: Fri, 16-Nov-84 10:27:23 EST
Article-I.D.: faron.162
Posted: Fri Nov 16 10:27:23 1984
Date-Received: Sat, 17-Nov-84 01:41:46 EST
Organization: The MITRE Corp., Bedford, Ma.
Lines: 9


	The number of palindromic primes is infinite. This follows from
the fact the the class of automorphic binary quadratic forms is also
infinite. See for example Dickson, Theory of Numbers pp. 111-115,
Dover Press . It is easy to see that the number of digits must be odd
because a palindrome of 2N digits will be a multiple of 10**N + 1.
That the number of digits does not have to be prime is also easy to
see by the example 131111131, which has 9 digits, yet is prime.