A267810 - OEIS

%I #8 Jan 21 2016 10:25:44

%S 1,0,0,1,1,1,0,1,1,1,1,1,0,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,0,1,1,1,

%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 217" 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="/A267810/b267810.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                 0 0 1

%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=217; 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 20 2016