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 A053919 #23 Feb 29 2024 23:08:44
%S A053919 25,225,55225,235225,3553225,33235225,252333225,2523555225,3325252225,
%T A053919 5232352225,3235555525225,232555332555225,35232553232323225,
%U A053919 32355552523523552532225,25532532332552235533223325522255225,332222523225232223533222222253253255253352335533253225
%N A053919 Squares composed of digits {2,3,5}.
%H A053919 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 A053919 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 A053919 H. Mishima <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/math02/math0210.htm#235">Squares consisted of 3 different digits</a>
%F A053919 a(n) = A053918(n)^2.
%o A053919 (Python) # see link in A053918 for a faster version
%o A053919 from math import isqrt
%o A053919 def aupto(limit):
%o A053919 alst, rootlimit = [], isqrt(limit)
%o A053919 for k in range(1, rootlimit+1):
%o A053919 if set(str(k*k)) <= set("235"): alst.append(k*k)
%o A053919 return alst
%o A053919 print(aupto(4*10**12)) # _Michael S. Branicky_, May 15 2021
%Y A053919 Cf. A053918.
%K A053919 nonn,base
%O A053919 1,1
%A A053919 _Patrick De Geest_, Mar 15 2000
%E A053919 More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 03 2005
%E A053919 One more term from Mishima's webpage added by _Max Alekseyev_, Jun 17 2011
%E A053919 a(16) from _Zhao Hui Du_, Feb 29 2024