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 A053888 #19 Aug 11 2024 14:41:32
%S A053888 1,3,11,173,3161,34827,43923,44623,54123,1108661,9603239,14832161,
%T A053888 9960980373,1513668461761,99961098929489127,459556524411439511,
%U A053888 145303131149776986249167839
%N A053888 Numbers k such that k^2 contains only digits {1,2,9}.
%H A053888 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 A053888 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 A053888 H. Mishima, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/math02/math0210.htm#129">Squares consisting of 3 different digits</a>
%Y A053888 Cf. A053889.
%K A053888 nonn,base,more
%O A053888 1,2
%A A053888 _Patrick De Geest_, Mar 15 2000
%E A053888 More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 04 2005
%E A053888 One more term from _Jon E. Schoenfield_, Sep 03 2006
%E A053888 Two more terms from Mishima's webpage added by _Max Alekseyev_, Jun 17 2011
%E A053888 a(17) from _Zhao Hui Du_, Feb 29 2024