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 A053956 #16 Oct 18 2019 21:30:03
%S A053956 2,8,26,88,2108238,8165033238,876154475408,2538991467974,
%T A053956 2728823494615908,253863101778786762,815277035409723028858892
%N A053956 Numbers k such that k^2 contains only digits {4,6,7}.
%H A053956 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 A053956 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 07 2009]
%Y A053956 Cf. A053957.
%K A053956 nonn,base,more
%O A053956 1,1
%A A053956 _Patrick De Geest_, Mar 15 2000
%E A053956 More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 04 2005
%E A053956 One more term from _Jon E. Schoenfield_, Sep 04 2006
%E A053956 Three more terms from Mishima's website added by _Max Alekseyev_, May 07 2009