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A270170
Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 110", based on the 5-celled von Neumann neighborhood.
1
1, 6, 14, 34, 54, 86, 134, 202, 278, 358, 454, 570, 710, 886, 1102, 1370, 1638, 1926, 2230, 2522, 2854, 3206, 3614, 4058, 4534, 5046, 5646, 6234, 6958, 7750, 8670, 9690, 10694, 11798, 12894, 13962, 15118, 16254, 17462, 18706, 19974, 21302, 22718, 24082
OFFSET
0,2
COMMENTS
Initialized with a single black (ON) cell at stage zero.
REFERENCES
S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 170.
MATHEMATICA
CAStep[rule_, a_]:=Map[rule[[10-#]]&, ListConvolve[{{0, 2, 0}, {2, 1, 2}, {0, 2, 0}}, a, 2], {2}];
code=110; stages=128;
rule=IntegerDigits[code, 2, 10];
g=2*stages+1; (* Maximum size of grid *)
a=PadLeft[{{1}}, {g, g}, 0, Floor[{g, g}/2]]; (* Initial ON cell on grid *)
ca=a;
ca=Table[ca=CAStep[rule, ca], {n, 1, stages+1}];
PrependTo[ca, a];
(* Trim full grid to reflect growth by one cell at each stage *)
k=(Length[ca[[1]]]+1)/2;
ca=Table[Table[Part[ca[[n]][[j]], Range[k+1-n, k-1+n]], {j, k+1-n, k-1+n}], {n, 1, k}];
on=Map[Function[Apply[Plus, Flatten[#1]]], ca] (* Count ON cells at each stage *)
Table[Total[Part[on, Range[1, i]]], {i, 1, Length[on]}] (* Sum at each stage *)
CROSSREFS
Cf. A270168.
Sequence in context: A269709 A270093 A270735 * A270986 A270323 A271772
KEYWORD
nonn,easy
AUTHOR
Robert Price, Mar 12 2016
STATUS
approved