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 A058420 #6 Aug 11 2024 14:41:33
%S A058420 1,770007001,71017701771000177071770101111001
%N A058420 Squares composed of digits {0,1,7}, not ending with zero.
%H A058420 P. De Geest, <a href="https://www.worldofnumbers.com/threedigits.htm">Index to related sequences</a>
%H A058420 Hisanori Mishima, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/math02/math0210.htm">Sporadic tridigital solutions</a>
%Y A058420 Cf. A058419.
%K A058420 nonn,base,hard,more,bref
%O A058420 1,2
%A A058420 _Patrick De Geest_, Nov 15 2000