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%I #11 Nov 02 2022 11:53:09
%S 1,8,16,36,40,68,72,116,128,180,204,256,292,332,368,500,480,492,700,
%T 592,820,760,976,992,1096,1132,1332,1344,1488,1580,1680,1812,1848,
%U 1996,2156,2168,2140,2624,2572,2680,3008,2980,3396,2960,3804,3356,4420,3868,4236,4284
%N Number of ON cells after n generations of the 2D cellular automaton described in the comments.
%C The cells are the squares of the standard square grid. All cells are initially OFF and one cell is turned ON at generation 1. At subsequent generations a cell is ON if and only if (1) exactly one of the four nearest side neighbors was ON or (2) exactly one of the four nearest corner neighbors was ON in the previous generation.(If exactly one side (corner) was ON, it does not matter how many corners (sides) were ON.)
%H John W. Layman, <a href="https://personal.math.vt.edu/layman/sequences/A194601.htm">Graphs of the automaton for generations 1-15</a>
%t (* Mathematica 8.0*) ca = CellularAutomaton[{2165730, {2, {{5, 1, 5}, {1, 0, 1}, {5, 1, 5}}}, {1, 1}}, {{{1}}, 0}, 50, 51]; a = Table[Total[ca[[i]], 2], {i, 1, 50}]
%K nonn
%O 1,2
%A _John W. Layman_, Aug 30 2011