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 A053884 #11 Aug 11 2024 14:41:32
%S A053884 1,11,1489,4596489,4144600242739,130834904430015239
%N A053884 Numbers k such that k^2 contains only digits {1,2,7}.
%H A053884 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 A053884 Hisanori Mishima, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/math02/math0210.htm#127">Sporadic tridigital solutions</a>
%Y A053884 Cf. A053885.
%K A053884 nonn,base,more
%O A053884 1,2
%A A053884 _Patrick De Geest_, Mar 15 2000
%E A053884 One more term from _Jon E. Schoenfield_, Sep 03 2006
%E A053884 One more term from Herman Jamke (hermanjamke(AT)fastmail.fm), Dec 23 2007