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 A053929 #31 Jul 16 2025 13:41:37
%S A053929 9,25,225,529,5929,29929,55225,99225,2295225,5929225,52229529,
%T A053929 552955225,2952292225,9559559529,59299555225,5929599995929,
%U A053929 9552259592929,5255925929995225,5555255292952225,92922592295555529529,959995929252599292299929255225,5955252925229529299525595522529225
%N A053929 Squares composed of digits {2,5,9}.
%C A053929 a(n) == 5 or 9 (mod 10). - _Chai Wah Wu_, Nov 30 2018
%H A053929 Zhao Hui Du, <a href="/A053929/b053929.txt">Table of n, a(n) for n = 1..26</a>
%H A053929 Patrick De Geest, <a href="http://www.worldofnumbers.com/threedigits.htm">Squares containing at most three distinct digits, Index entries for related sequences</a>.
%H A053929 Hisanori Mishima, <a href="https://www.asahi-net.or.jp/~KC2H-MSM/mathland/math02/math0210.htm#259">Sporadic tridigital solutions</a>.
%H A053929 Author?, <a href="http://web.archive.org/web/20080708203024/http://blue.kakiko.com/mmrmmr/htm/eqtn06.html">Source</a>, (<a href="http://web.archive.org/web/20060426155831/http://blue.kakiko.com/mmrmmr/txt/eqtn06.txt">txt</a>)
%F A053929 a(n) = A053928(n)^2. - _Elmo R. Oliveira_, Jul 16 2025
%t A053929 Flatten[Table[Select[FromDigits /@ Tuples[{2, 5, 9}, n], IntegerQ[Sqrt[#]] &], {n, 6}]] (* _Amiram Eldar_, Nov 30 2018 *)
%Y A053929 Cf. A053928.
%K A053929 nonn,base
%O A053929 1,1
%A A053929 _Patrick De Geest_, Mar 15 2000
%E A053929 One more term from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 14 2005