%I A118108
%S A118108 1,7,17,119,273,1911,4369,30583,69905,489335,1118481,7829367,17895697,
%T A118108 125269879,286331153,2004318071,4581298449,32069089143,73300775185,
%U A118108 513105426295,1172812402961,8209686820727,18764998447377
%N A118108 Decimal representation of n-th iteration of the Rule 54 elementary cellular 
               automaton starting with a single black cell.
%H A118108 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Rule54.html">Rule 54</a>
%H A118108 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               ElementaryCellularAutomaton.html">Elementary Cellular Automaton</
               a>
%F A118108 a(n odd) = 7(4^(n+1)-1)/5, a(n even) = (4^(n+2)-1)/15
%e A118108 1; 1, 1, 1; 1, 0, 0, 0, 1; 1, 1, 1, 0, 1, 1, 1; 1, 0, 0, 0, 1, 0, 0, 
               0, 1; ...
%Y A118108 Cf. A118109.
%Y A118108 Sequence in context: A067185 A063384 A165246 this_sequence A147643 A061159 
               A140122
%Y A118108 Adjacent sequences: A118105 A118106 A118107 this_sequence A118109 A118110 
               A118111
%K A118108 nonn,tabf
%O A118108 0,2
%A A118108 Eric Weisstein (eric(AT)weisstein.com), Apr 13, 2006