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 A029999 #14 Feb 10 2025 21:31:06
%S A029999 0,1,4,9,196,784,28900,33489,38416,43681,94864,115600,124609,133956,
%T A029999 4831204,5664400,6563844,8398404,16208676,17994564,19324816,20958084,
%U A029999 50098084,58706244,815787844,825470361,835210000,845006761,946915984
%N A029999 Squares which are palindromes in base 13.
%H A029999 Vincenzo Librandi, <a href="/A029999/b029999.txt">Table of n, a(n) for n = 1..61</a>
%H A029999 Patrick De Geest, <a href="https://www.worldofnumbers.com/nobase10pg2.htm">Palindromic Squares in bases 2 to 17</a>
%t A029999 pb13Q[n_]:=Module[{idn13=IntegerDigits[n, 13]}, idn13==Reverse[idn13]]; Select[Range[0, 20000]^2, pb13Q] (* _Vincenzo Librandi_, Jul 24 2014 *)
%Y A029999 Cf. A002779, A029734, A029738, A029806, A029983, A029985, A029987, A029989, A029991, A029993, A029995, A029997, A030074, A030075.
%K A029999 nonn,base
%O A029999 1,3
%A A029999 _Patrick De Geest_