cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A288333 Binary representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 443", based on the 5-celled von Neumann neighborhood.

This page as a plain text file.
%I A288333 #8 Feb 16 2025 08:33:47
%S A288333 1,11,110,111,11000,111111,111000,11011111,111100000,111111111,
%T A288333 11000000000,111111111111,111000000000,11011111111111,111111110000000,
%U A288333 1111111111111,11111111000000000,11111111111111111,1100111100000000000,11111111111111111111
%N A288333 Binary representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 443", based on the 5-celled von Neumann neighborhood.
%C A288333 Initialized with a single black (ON) cell at stage zero.
%D A288333 S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 170.
%H A288333 Robert Price, <a href="/A288333/b288333.txt">Table of n, a(n) for n = 0..126</a>
%H A288333 Robert Price, <a href="/A288333/a288333.tmp.txt">Diagrams of first 20 stages</a>
%H A288333 N. J. A. Sloane, <a href="http://arxiv.org/abs/1503.01168">On the Number of ON Cells in Cellular Automata</a>, arXiv:1503.01168 [math.CO], 2015
%H A288333 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ElementaryCellularAutomaton.html">Elementary Cellular Automaton</a>
%H A288333 S. Wolfram, <a href="http://wolframscience.com/">A New Kind of Science</a>
%H A288333 Wolfram Research, <a href="http://atlas.wolfram.com/">Wolfram Atlas of Simple Programs</a>
%H A288333 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a>
%H A288333 <a href="https://oeis.org/wiki/Index_to_2D_5-Neighbor_Cellular_Automata">Index to 2D 5-Neighbor Cellular Automata</a>
%H A288333 <a href="https://oeis.org/wiki/Index_to_Elementary_Cellular_Automata">Index to Elementary Cellular Automata</a>
%t A288333 CAStep[rule_, a_] := Map[rule[[10 - #]] &, ListConvolve[{{0, 2, 0},{2, 1, 2}, {0, 2, 0}}, a, 2],{2}];
%t A288333 code = 443; stages = 128;
%t A288333 rule = IntegerDigits[code, 2, 10];
%t A288333 g = 2 * stages + 1; (* Maximum size of grid *)
%t A288333 a = PadLeft[{{1}}, {g, g}, 0,Floor[{g, g}/2]]; (* Initial ON cell on grid *)
%t A288333 ca = a;
%t A288333 ca = Table[ca = CAStep[rule, ca], {n, 1, stages + 1}];
%t A288333 PrependTo[ca, a];
%t A288333 (* Trim full grid to reflect growth by one cell at each stage *)
%t A288333 k = (Length[ca[[1]]] + 1)/2;
%t A288333 ca = Table[Table[Part[ca[[n]] [[j]],Range[k + 1 - n, k - 1 + n]], {j, k + 1 - n, k - 1 + n}], {n, 1, k}];
%t A288333 Table[FromDigits[Part[ca[[i]] [[i]], Range[i, 2 * i - 1]], 10], {i, 1, stages - 1}]
%Y A288333 Cf. A288332, A288334, A288335.
%K A288333 nonn,easy
%O A288333 0,2
%A A288333 _Robert Price_, Jun 07 2017