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 A180115 #4 Nov 02 2016 15:15:01 %S A180115 1,111,222,22222,33333,3333333,4444444,444444444,555555555, %T A180115 55555555555,66666666666,6666666666666,7777777777777,777777777777777, %U A180115 888888888888888 %N A180115 A109613(n)-fold concatenation of A008619(n). %Y A180115 Cf. A000217, A109613, A008619 %K A180115 nonn,base,less %O A180115 1,2 %A A180115 _Mark Dols_, Aug 10 2010 %E A180115 Definition rephrased, kewyord:base,less added - _R. J. Mathar_, Aug 19 2010