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 A058442 #15 Jul 16 2025 17:53:17
%S A058442 4,484,40804,88804,4008004,4088484,4848804,400080004,400880484,
%T A058442 484088004,840884004,40000800004,40008800484,40080840804,40804808004,
%U A058442 48400880004,400084080484,4000008000004,4000088000484,4000808040804,4080408080004,4080488880484,4840008800004
%N A058442 Squares composed of digits {0,4,8}, not ending with zero.
%H A058442 Zhao Hui Du, <a href="/A058442/b058442.txt">Table of n, a(n) for n = 1..4000</a>
%H A058442 Patrick De Geest, <a href="http://www.worldofnumbers.com/threedigits.htm">Index to related sequences</a>.
%H A058442 Hisanori Mishima, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/math02/math0210.htm#048">Sporadic tridigital solutions</a>.
%F A058442 a(n) = A058441(n)^2. - _Elmo R. Oliveira_, Jul 16 2025
%t A058442 Select[FromDigits/@Tuples[{0,4,8},13],Mod[#,10]!=0&&IntegerQ[Sqrt[#]]&] (* _Harvey P. Dale_, Feb 14 2023 *)
%Y A058442 Cf. A058441.
%K A058442 nonn,base
%O A058442 1,1
%A A058442 _Patrick De Geest_, Nov 15 2000