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 A038690 #17 May 05 2017 12:34:16
%S A038690 0,1,5,6,2,5,4,24,9,3,10,34,11,37,12,34,4,42,43,14,45,11,15,48,18,5,
%T A038690 51,52,17,23,48,56,18,58,59,66,6,61,62,63,20,21,65,66,12,116,68,69,22,
%U A038690 7,50,72,23,73,74,166,16,24,126,77,40,19,25,128,8,81,108,26,41,13,52,131
%N A038690 a(n)^2 is smallest square containing the string 'n'.
%C A038690 "Containment" implies here that the digits of n are consecutive digits in the square; see A091873 for a relaxed alternative. [_R. J. Mathar_, Dec 09 2008]
%H A038690 Michael De Vlieger, <a href="/A038690/b038690.txt">Table of n, a(n) for n = 0..10000</a>
%t A038690 Table[ i=0; While[ StringPosition[ ToString[ i^2 ], ToString[ n ] ]=={}, i++ ]; i, {n, 0, 80} ]
%Y A038690 Cf. A018851, A029944, A068165, A091873.
%K A038690 base,nonn
%O A038690 0,3
%A A038690 _Hans Havermann_