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 A169649 Total number of cells that are ON at stage n in Wolfram's 2-D cellular automaton defined by Rule 942. 4
 0, 1, 5, 9, 21, 29, 41, 53, 89, 117, 129, 141, 177, 205, 241, 277, 385, 485, 497, 509, 545, 573, 609, 645, 753, 845, 881, 917, 1025, 1109, 1217, 1325, 1649, 1989, 2001, 2013, 2049, 2077, 2113, 2149, 2257, 2349, 2385, 2421, 2529, 2613, 2721, 2829 (list; graph; refs; listen; history; text; internal format)
 OFFSET -1,3 COMMENTS We work on the square grid. A cell is turned ON iff exactly one or four of its four neighbors is ON. Once a cell is ON it stays ON. At stage -1 all cells are OFF. At stage 0 a single cell is turned ON. REFERENCES S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 928. LINKS N. J. A. Sloane, Table of n, a(n) for n = -1..549 David Applegate, The movie version David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata, Congressus Numerantium, Vol. 206 (2010), 157-191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n-1)-1) for n >= 2.] N. J. A. Sloane, Illustration of first 24 generations (png) N. J. A. Sloane, Illustration of first 24 generations (pdf) N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS MATHEMATICA Map[Function[Apply[Plus, Flatten[ #1]]], CellularAutomaton[{ 942, {2, {{0, 2, 0}, {2, 1, 2}, {0, 2, 0}}}, {1, 1}}, {{{1}}, 0}, 100]] ArrayPlot /@ CellularAutomaton[{942, {2, {{0, 2, 0}, {2, 1, 2}, {0, 2, 0}}}, {1, 1}}, {{{1}}, 0}, 23] CROSSREFS Partial sums of A169648. Sequence in context: A186297 A272986 A273642 * A273739 A169709 A269523 Adjacent sequences:  A169646 A169647 A169648 * A169650 A169651 A169652 KEYWORD nonn AUTHOR N. J. A. Sloane, Apr 07 2010 EXTENSIONS Added Mma programs and illustrations. - N. J. A. Sloane, Sep 21 2014 STATUS approved

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Last modified October 14 02:29 EDT 2019. Contains 327995 sequences. (Running on oeis4.)