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 A030175 #22 Feb 16 2025 08:32:35
%S A030175 1,11,111,36361,363639,461761,3636361,34815389,362397739,176412364139,
%T A030175 57637950363639,3497458093147239,56843832676142723489,
%U A030175 557963558954625926861
%N A030175 When squared gives number composed of digits {1,2,3}.
%H A030175 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 A030175 Author?, <a href="http://web.archive.org/web/20080517071411/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://web.archive.org/web/20060426155831/http://blue.kakiko.com/mmrmmr/txt/eqtn06.txt">txt</a>)
%H A030175 Hisanori Mishima, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/math02/math0210.htm">Sporadic tridigital solutions</a>
%H A030175 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SquareNumber.html">Square Number.</a>
%H A030175 <a href="/index/Sq#squares">Index entries for sequences related to squares</a>.
%F A030175 a(n)^2 = A030174(n). - _M. F. Hasler_, Nov 16 2017
%t A030175 Do[ If[ Union[ Join[{1, 2, 3}, IntegerDigits[n^2] ] ] == {1, 2, 3}, Print[n] ], {n, 0, 10^9}]
%o A030175 (PARI) lista(nn) = for(n=1, nn, if(setminus(vecsort(digits(n^2), , 8), [1, 2, 3])==[], print1(n, ", "))) \\ _Iain Fox_, Nov 16 2017
%Y A030175 Cf. A030174; A000290.
%Y A030175 Cf. A006716 = A027675^2, A030176 = A030177^2, A058411^2 = A058412, ..., A058473^2 = A058474.
%Y A030175 Cf. A136808, A136809, ..., A137147: n and n^2 have digits {...}.
%Y A030175 Cf. A277959^2 = A277946 and A277960^2 = A277947: squares whose largest digit is 2 resp. 3.
%K A030175 nonn,base
%O A030175 1,2
%A A030175 _Patrick De Geest_
%E A030175 More terms from _Patrick De Geest_, Mar 01 2000
%E A030175 More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 14 2005
%E A030175 Offset corrected by _Iain Fox_, Nov 16 2017