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 A113818 #11 May 21 2020 19:38:31 %S A113818 1,1,2,3,3,4,5,5,6,7,7,9,0,0,1,2,2,3,4,4,5,6,6,7,8,9 %N A113818 Decimal expansion of the integer (101101101101101101101101101)/9. %C A113818 Using square roots and periodic numbers you can produce this kind of curious sequence. %H A113818 R. Miyadera, <a href="http://library.wolfram.com/infocenter/MathSource/5948/">Interesting patterns made by periodic numbers and square root</a>. %F A113818 (101101101101101101101101101)/9 or Sqrt[101101101101101101101101101], where sqrt is the square root. %e A113818 (101101101101101101101101101)/9 = 11233455677900122344566789. %t A113818 RealDigits[101101101101101101101101101/9,10,26][[1]] (* _Harvey P. Dale_, May 21 2020 *) %Y A113818 Cf. A021085, A021895, A113694, A113675. %K A113818 easy,nonn,cons,fini,full %O A113818 26,3 %A A113818 _Ryohei Miyadera_ and Daisuke Minematsu, Jan 23 2006 %E A113818 Edited by _N. J. A. Sloane_, May 26 2006 %E A113818 Previous Mathematica program replaced by _Harvey P. Dale_, May 21 2020