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 A058414 #10 Jul 18 2025 22:02:21
%S A058414 1,4,144,441,1444,10404,40401,1004004,1100401,4004001,100040004,
%T A058414 114041041,400040001,414041104,10000400004,10110101401,40000400001,
%U A058414 41011110144,141001001001,414441100441,1000004000004,1041110041104,4000004000001,4011400111104,100000040000004
%N A058414 Squares composed of digits {0,1,4}, not ending with zero.
%H A058414 Patrick De Geest, <a href="https://www.worldofnumbers.com/threedigits.htm">Index to related sequences</a>.
%H A058414 Hisanori Mishima, <a href="https://www.asahi-net.or.jp/~KC2H-MSM/mathland/math02/math0210.htm#014">Sporadic tridigital solutions</a>.
%F A058414 a(n) = A058413(n)^2. - _Elmo R. Oliveira_, Jul 18 2025
%Y A058414 Cf. A058413.
%K A058414 nonn,base
%O A058414 1,2
%A A058414 _Patrick De Geest_, Nov 15 2000
%E A058414 More terms added using A058413 by _Elmo R. Oliveira_, Jul 18 2025