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 A071054 #26 Mar 16 2017 14:34:02
%S A071054 1,3,4,5,7,7,10,9,13,11,16,13,19,15,22,17,25,19,28,21,31,23,34,25,37,
%T A071054 27,40,29,43,31,46,33,49,35,52,37,55,39,58,41,61,43,64,45,67,47,70,49,
%U A071054 73,51,76,53,79,55,82,57,85,59,88,61,91,63,94,65,97,67,100,69
%N A071054 a(2n)=3n+1, a(2n+1)=2n+2.
%C A071054 Number of ON cells at n-th generation of 1-D CA defined by Rule 158, starting with a single ON cell at generation 0. Equivalently, number of 1's in n-th row of triangle in A071037. - _N. J. A. Sloane_, Aug 10 2014
%D A071054 S. Wolfram, A New Kind of Science, Wolfram Media, 2002; Chapter 3.
%H A071054 Vincenzo Librandi, <a href="/A071054/b071054.txt">Table of n, a(n) for n = 0..1000</a>
%H A071054 A. J. Macfarlane, <a href="http://www.damtp.cam.ac.uk/user/ajm/Papers2016/GFsForCAsOfEvenRuleNo.ps">Generating functions for integer sequences defined by the evolution of cellular automata with even rule numbers</a>, 2016.
%H A071054 N. J. A. Sloane, <a href="/A071054/a071054.png">Illustration of first 20 generations of Rule 158</a>
%H A071054 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a>
%F A071054 G.f.: (-x^3+2x^2+3x+1)/(1-x^2)^2.
%F A071054 a(n) = (5/4)*n + 3/2 + (n/4 - 1/2)*(-1)^n. - _Robert Israel_, Aug 11 2014
%t A071054 CoefficientList[Series[(-x^3 + 2 x^2 + 3 x + 1)/(1 - x^2)^2, {x, 0, 100}], x] (* _Vincenzo Librandi_, Aug 11 2014 *)
%t A071054 ArrayPlot[CellularAutomaton[158, {{1}, 0}, 20]] (* _N. J. A. Sloane_, Aug 11 2014 *)
%Y A071054 Cf. A029578.
%K A071054 nonn
%O A071054 0,2
%A A071054 _Hans Havermann_, May 26 2002
%E A071054 Simpler definition from _N. J. A. Sloane_, Aug 11 2014