This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A029973 #16 Aug 11 2024 14:41:30
%S A029973 2,3,31,41,67,83,109,701,911,1091,1171,1277,1327,1667,1847,2083,2213,
%T A029973 2293,2423,2473,2579,2659,2789,2969,3049,16001,16651,19531,20431,
%U A029973 21481,23311,23561,24611,25391,26041,27091,28921,30871,31121
%N A029973 Primes that are palindromic in base 5.
%H A029973 John Cerkan, <a href="/A029973/b029973.txt">Table of n, a(n) for n = 1..10000</a>
%H A029973 P. De Geest, <a href="https://www.worldofnumbers.com/palpri.htm">World!Of Palindromic Primes</a>
%t A029973 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 A029973 nonn,base
%O A029973 1,1
%A A029973 _Patrick De Geest_