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Primes that are palindromic in base 5.
7

%I #16 Aug 11 2024 14:41:30

%S 2,3,31,41,67,83,109,701,911,1091,1171,1277,1327,1667,1847,2083,2213,

%T 2293,2423,2473,2579,2659,2789,2969,3049,16001,16651,19531,20431,

%U 21481,23311,23561,24611,25391,26041,27091,28921,30871,31121

%N Primes that are palindromic in base 5.

%H John Cerkan, <a href="/A029973/b029973.txt">Table of n, a(n) for n = 1..10000</a>

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

%t f[n_]:=FromDigits[RealDigits[n,5][[1]]]==FromDigits[Reverse[RealDigits[n,5][[1]]]]; lst={}; Do[p=Prime[n]; If[f[p],AppendTo[lst,p]],{n,8!}]; lst (* _Vladimir Joseph Stephan Orlovsky_, Aug 10 2009 *)

%K nonn,base

%O 1,1

%A _Patrick De Geest_