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 A053948 #24 Aug 11 2024 14:41:32
%S A053948 3,6,63,264,306,1914,3114,31086,81813,190614,251787,310956,
%T A053948 184372811544,631933060806,3152295978114,629836198308687,
%U A053948 2576231033241456,18430047920827535573187,31047286456844613647179386
%N A053948 Numbers k such that k^2 contains only digits {3,6,9}.
%H A053948 P. De Geest, <a href="https://www.worldofnumbers.com/threedigits.htm">Squares containing at most three distinct digits, Index entries for related sequences</a>
%H A053948 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>)
%H A053948 H. Mishima, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/math02/math0210.htm#369">Sporadic tridigital solutions</a>
%Y A053948 Cf. A053949.
%K A053948 nonn,base,more
%O A053948 1,1
%A A053948 _Patrick De Geest_, Mar 15 2000
%E A053948 More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 14 2005
%E A053948 One more term from _Jon E. Schoenfield_, Sep 04 2006
%E A053948 Three more terms from Mishima's webpage added by _Max Alekseyev_, Jun 17 2011
%E A053948 One more term from _Zhao Hui Du_, Mar 01 2024