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A194601
Number of ON cells after n generations of the 2D cellular automaton described in the comments.
1
1, 8, 16, 36, 40, 68, 72, 116, 128, 180, 204, 256, 292, 332, 368, 500, 480, 492, 700, 592, 820, 760, 976, 992, 1096, 1132, 1332, 1344, 1488, 1580, 1680, 1812, 1848, 1996, 2156, 2168, 2140, 2624, 2572, 2680, 3008, 2980, 3396, 2960, 3804, 3356, 4420, 3868, 4236, 4284
OFFSET
1,2
COMMENTS
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.)
MATHEMATICA
(* 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}]
CROSSREFS
Sequence in context: A058516 A366511 A217672 * A200271 A197986 A054301
KEYWORD
nonn
AUTHOR
John W. Layman, Aug 30 2011
STATUS
approved