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 A029978 #19 Aug 11 2024 14:41:30
%S A029978 2,3,5,7,199,277,421,443,499,521,587,643,709,743,787,809,887,953,1009,
%T A029978 1031,1109,1153,1231,1297,1319,15731,16831,19031,19273,20857,22441,
%U A029978 23057,25741,27809,28183,28909,31231,32089,32573,34157,35257
%N A029978 Primes that are palindromic in base 11.
%H A029978 John Cerkan, <a href="/A029978/b029978.txt">Table of n, a(n) for n = 1..10000</a>
%H A029978 P. De Geest, <a href="https://www.worldofnumbers.com/palpri.htm">World!Of Palindromic Primes</a>
%t A029978 f[n_]:=FromDigits[RealDigits[n,11][[1]]]==FromDigits[Reverse[RealDigits[n,11][[1]]]]; lst={}; Do[p=Prime[n]; If[f[p],AppendTo[lst,p]],{n,8!}]; lst (* _Vladimir Joseph Stephan Orlovsky_, Aug 10 2009 *)
%t A029978 Select[Prime@ Range@ 4000, PalindromeQ@ IntegerDigits[#, 11] &] (* _Michael De Vlieger_, May 16 2017, Version 10.3 *)
%o A029978 (PARI) isok(n) = if (isprime(n), my(d=digits(n, 11)); d == Vecrev(d)); \\ _Michel Marcus_, May 15 2017
%K A029978 nonn,base
%O A029978 1,1
%A A029978 _Patrick De Geest_