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 A029994 #20 Feb 10 2025 19:57:53
%S A029994 0,1,2,10,20,82,91,100,164,730,820,1460,6562,6643,6724,7300,7381,7462,
%T A029994 13124,13642,13660,14281,54050,59050,59860,65620,66430,118100,123010,
%U A029994 126286,161410,161896,487750,531442,532171
%N A029994 Numbers k such that k^2 is palindromic in base 9.
%H A029994 Seiichi Manyama, <a href="/A029994/b029994.txt">Table of n, a(n) for n = 1..100</a>
%H A029994 Patrick De Geest, <a href="https://www.worldofnumbers.com/nobase10pg2.htm">Palindromic Squares in bases 2 to 17</a>
%t A029994 pb9Q[n_]:=Module[{idn=IntegerDigits[n^2,9]},idn==Reverse[idn]]; Select[ Range[0,600000],pb9Q] (* _Harvey P. Dale_, Sep 29 2013 *)
%Y A029994 Cf. A007095.
%Y A029994 Numbers k such that k^2 is palindromic in base b: A003166 (b=2), A029984 (b=3), A029986 (b=4), A029988 (b=5), A029990 (b=6), A029992 (b=7), A029805 (b=8), this sequence (b=9), A002778 (b=10), A029996 (b=11), A029737 (b=12), A029998 (b=13), A030072 (b=14), A030073 (b=15), A029733 (b=16), A118651 (b=17).
%K A029994 nonn,base
%O A029994 1,3
%A A029994 _Patrick De Geest_