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 A029989 #17 Feb 10 2025 19:56:02
%S A029989 0,1,4,36,676,961,4356,15876,24336,391876,423801,571536,646416,
%T A029989 9771876,10732176,14107536,81974916,244171876,248094001,264908176,
%U A029989 339812356,351787536,1061326084,1167042244,2181263616,6103671876
%N A029989 Squares which are palindromes in base 5.
%H A029989 Chai Wah Wu, <a href="/A029989/b029989.txt">Table of n, a(n) for n = 1..147</a>
%H A029989 Patrick De Geest, <a href="https://www.worldofnumbers.com/nobase10pg2.htm">Palindromic Squares in bases 2 to 17</a>
%H A029989 G. J. Simmons, <a href="/A002778/a002778.pdf">On palindromic squares of non-palindromic numbers</a>, J. Rec. Math., 5 (No. 1, 1972), 11-19. [Annotated scanned copy]
%t A029989 pal5Q[n_]:=Module[{idn5=IntegerDigits[n,5]},idn5==Reverse[idn5]]; Select[ Range[0,80000]^2,pal5Q] (* _Harvey P. Dale_, May 05 2012 *)
%Y A029989 Cf. A002778, A003166, A263611, A263612, A029988.
%K A029989 nonn,base
%O A029989 1,3
%A A029989 _Patrick De Geest_