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A028981 Primes p such that p+1 is palindromic. 1

%I #16 Aug 25 2016 15:01:36

%S 2,3,5,7,43,211,241,251,271,281,433,443,463,827,857,877,887,2111,2221,

%T 2441,2551,4003,4663,4993,8117,8447,8887,20101,20201,21011,21211,

%U 21611,21911,22621,22721,22921,23131,23431,23531,23831,24841

%N Primes p such that p+1 is palindromic.

%H Harvey P. Dale, <a href="/A028981/b028981.txt">Table of n, a(n) for n = 1..750</a>

%H Patrick De Geest, <a href="http://www.worldofnumbers.com/palpri.htm">World!Of Palindromic Primes</a>

%t palQ[n_] := Module[{idn = IntegerDigits[n + 1], len = Floor[IntegerLength[n + 1]/2]}, Take[idn, len] == Reverse[Take[idn, -len]]]; Select[Prime[Range[2800]], palQ] (* _Harvey P. Dale_, Nov 04 2011 *)

%t Select[Prime[Range[2800]], Reverse[x = IntegerDigits[# + 1]] == x &] (* _Jayanta Basu_, Jun 05 2013 *)

%Y Cf. A027713.

%K nonn,base

%O 1,1

%A _Patrick De Geest_

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Last modified April 23 18:16 EDT 2024. Contains 371916 sequences. (Running on oeis4.)