%I #8 Jan 20 2016 09:26:59
%S 1,1,0,0,1,1,0,1,1,1,1,1,0,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,0,1,1,1,
%T 1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,
%U 1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,1,1
%N Triangle read by rows giving successive states of cellular automaton generated by "Rule 203" initiated with a single ON (black) cell.
%C Row n has length 2n+1.
%D S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.
%H Robert Price, <a href="/A267683/b267683.txt">Table of n, a(n) for n = 0..10000</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/ElementaryCellularAutomaton.html">Elementary Cellular Automaton</a>
%H S. Wolfram, <a href="http://wolframscience.com/">A New Kind of Science</a>
%H <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a>
%H <a href="https://oeis.org/wiki/Index_to_Elementary_Cellular_Automata">Index to Elementary Cellular Automata</a>
%e The first ten rows:
%e 1
%e 1 0 0
%e 1 1 0 1 1
%e 1 1 1 0 1 1 1
%e 1 1 1 1 0 1 1 1 1
%e 1 1 1 1 1 0 1 1 1 1 1
%e 1 1 1 1 1 1 0 1 1 1 1 1 1
%e 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1
%e 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1
%e 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1
%t rule=203; rows=20; ca=CellularAutomaton[rule,{{1},0},rows-1,{All,All}]; (* Start with single black cell *) catri=Table[Take[ca[[k]],{rows-k+1,rows+k-1}],{k,1,rows}]; (* Truncated list of each row *) Flatten[catri] (* Triangle Representation of CA *)
%K nonn,tabf,easy
%O 0
%A _Robert Price_, Jan 19 2016