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A246311 Number of ON cells at generation n of 2-D cellular automaton in which a cell is ON iff either 1 or 2 of its eight neighbors were ON at previous generation, starting with a single ON cell. 1

%I

%S 1,8,16,24,28,56,68,88,112,116,148,216,232,260,400,320,420,440,508,

%T 472,512,564,752,684,876,896,1064,1064,1224,1368,1620,1396,1564,1612,

%U 1756,1632,1976,1676,2008,1848,2016,2080,2332,2004,2488,2332,2988,2516,2868,3008,3184,2956,3476,3432,3556,3532,4008,4116,4676,4308,4984,5044,6044,5148,5780,5780,6200

%N Number of ON cells at generation n of 2-D cellular automaton in which a cell is ON iff either 1 or 2 of its eight neighbors were ON at previous generation, starting with a single ON cell.

%C This is the Rule 60 outer totalistic 8-neighbor 2-D CA.

%C The first few generations are easy to understand, but then there are complications (hence the keyword "look", which refers to the illustrations).

%H N. J. A. Sloane, <a href="/A246311/a246311.pdf">Illustration of first 28 generations</a>

%t Total@*Total /@ CellularAutomaton[{60, {2, {{2, 2, 2}, {2, 1, 2}, {2, 2, 2}}}, {1, 1}}, {{{1}}, 0}, 66]

%t ArrayPlot /@ CellularAutomaton[{60, {2, {{2, 2, 2}, {2, 1, 2}, {2, 2, 2}}}, {1, 1}}, {{{1}}, 0}, 28]

%K nonn,look

%O 0,2

%A _N. J. A. Sloane_, Aug 23 2014

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Last modified December 6 16:24 EST 2019. Contains 329808 sequences. (Running on oeis4.)