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 A246309 Number of ON cells at generation n of 2-D cellular automaton in which a cell is ON iff either 1, 2 or 4 of its eight neighbors were ON at previous generation, starting with a single ON cell. 1
 1, 8, 20, 32, 44, 64, 65, 149, 96, 184, 161, 312, 236, 356, 312, 545, 397, 552, 524, 821, 565, 872, 688, 1129, 929, 1152, 1245, 1440, 1460, 1485, 1737, 1904, 1592, 2240, 1757, 2433, 2080, 2520, 2404, 2956, 2620, 3200, 3041, 3629, 3133, 3928, 3513, 4385, 3668, 4469, 4300, 4748, 4309, 5420, 4917, 5841, 5232, 6161, 5521, 6853, 5701, 7448, 6088, 8241, 6165, 7964, 6945 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS This is the Rule 828 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 N. J. A. Sloane, Illustration of first 28 generations. MATHEMATICA Total@*Total /@ CellularAutomaton[{828, {2, {{2, 2, 2}, {2, 1, 2}, {2, 2, 2}}}, {1, 1}}, {{{1}}, 0}, 66] ArrayPlot /@ CellularAutomaton[{828, {2, {{2, 2, 2}, {2, 1, 2}, {2, 2, 2}}}, {1, 1}}, {{{1}}, 0}, 28] CROSSREFS Sequence in context: A246308 A194218 A017617 * A038522 A267435 A186293 Adjacent sequences:  A246306 A246307 A246308 * A246310 A246311 A246312 KEYWORD nonn,look AUTHOR N. J. A. Sloane, Aug 23 2014 STATUS approved

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Last modified December 13 17:37 EST 2019. Contains 329970 sequences. (Running on oeis4.)