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 A053900 #23 Mar 09 2024 18:23:55
%S A053900 1,2,9,12,21,22,29,38,109,122,221,1191,20359,12017441,64352012,
%T A053900 69362229,105741122,1347014779,10715008859,664190348029,940313186572,
%U A053900 4263966676478,34479242283029,1055656895701022,2968363385585478
%N A053900 Numbers k such that k^2 contains only digits {1,4,8}.
%H A053900 Zhao Hui Du, <a href="/A053900/b053900.txt">Table of n, a(n) for n = 1..31</a>
%H A053900 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 A053900 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 A053900 H. Mishima, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/math02/math0210.htm">Squares consisted of 3 different digits</a> [From _Max Alekseyev_, May 29 2009]
%Y A053900 Cf. A053901.
%K A053900 nonn,base
%O A053900 1,2
%A A053900 _Patrick De Geest_, Mar 15 2000
%E A053900 More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 04 2005
%E A053900 Two more terms from _Jon E. Schoenfield_, Sep 03 2006
%E A053900 Further terms from Mishima's webpage added by _Max Alekseyev_, May 29 2009