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 A246310 Number of ON cells at generation n of 2-D cellular automaton in which a cell is ON iff either 1 or 4 of its eight neighbors were ON at previous generation, starting with a single ON cell. 2
 1, 8, 8, 25, 4, 32, 32, 100, 25, 61, 88, 208, 112, 164, 232, 380, 188, 304, 341, 596, 437, 576, 528, 696, 553, 749, 736, 924, 1016, 1060, 1161, 1372, 1200, 1388, 1456, 1720, 1493, 1761, 1660, 2072, 1781, 2084, 1973, 2732, 2252, 2596, 2552, 3121, 2684, 3145, 2972, 3828, 3132, 3588, 3480, 4061, 3772, 4073, 4009, 4929, 4264, 4996, 4845, 5493, 5160, 5804, 5156 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS This is the Rule 780 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. N. J. A. Sloane, On the Number of ON Cells in Cellular Automata, arXiv:1503.01168, 2015 MATHEMATICA Total@*Total /@ CellularAutomaton[{780, {2, {{2, 2, 2}, {2, 1, 2}, {2, 2, 2}}}, {1, 1}}, {{{1}}, 0}, 66] ArrayPlot /@ CellularAutomaton[{780, {2, {{2, 2, 2}, {2, 1, 2}, {2, 2, 2}}}, {1, 1}}, {{{1}}, 0}, 28] CROSSREFS Cf. A253086 (5-celled analog). Sequence in context: A160239 A211017 A037018 * A318542 A319089 A003873 Adjacent sequences:  A246307 A246308 A246309 * A246311 A246312 A246313 KEYWORD nonn,look AUTHOR N. J. A. Sloane, Aug 23 2014 STATUS approved

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Last modified January 20 12:50 EST 2019. Contains 319330 sequences. (Running on oeis4.)