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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
1, 8, 16, 24, 28, 56, 68, 88, 112, 116, 148, 216, 232, 260, 400, 320, 420, 440, 508, 472, 512, 564, 752, 684, 876, 896, 1064, 1064, 1224, 1368, 1620, 1396, 1564, 1612, 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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

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

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

LINKS

Table of n, a(n) for n=0..66.

N. J. A. Sloane, Illustration of first 28 generations

MATHEMATICA

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

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

CROSSREFS

Sequence in context: A046099 A033859 A177899 * A244371 A144566 A037989

Adjacent sequences:  A246308 A246309 A246310 * A246312 A246313 A246314

KEYWORD

nonn,look

AUTHOR

N. J. A. Sloane, Aug 23 2014

STATUS

approved

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Last modified November 14 02:19 EST 2019. Contains 329108 sequences. (Running on oeis4.)