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A266671
Decimal representation of the n-th iteration of the "Rule 53" elementary cellular automaton starting with a single ON (black) cell.
3
1, 3, 8, 95, 64, 1791, 512, 30719, 4096, 507903, 32768, 8257535, 262144, 133169151, 2097152, 2139095039, 16777216, 34292629503, 134217728, 549218942975, 1073741824, 8791798054911, 8589934592, 140703128616959, 68719476736, 2251524935778303, 549755813888
OFFSET
0,2
FORMULA
Conjectures from Colin Barker, Jan 03 2016 and Apr 18 2019: (Start)
a(n) = 25*a(n-2) - 152*a(n-4) + 128*a(n-6) for n>5.
G.f.: (1+3*x-17*x^2+20*x^3+16*x^4-128*x^5) / ((1-x)*(1+x)*(1-4*x)*(1+4*x)*(1-8*x^2)).
(End)
MATHEMATICA
rule=53; rows=20; ca=CellularAutomaton[rule, {{1}, 0}, rows-1, {All, All}]; (* Start with single black cell *) catri=Table[Take[ca[[k]], {rows-k+1, rows+k-1}], {k, 1, rows}]; (* Truncated list of each row *) Table[FromDigits[catri[[k]], 2], {k, 1, rows}] (* Decimal Representation of Rows *)
CROSSREFS
Sequence in context: A070901 A079657 A136309 * A069703 A114737 A233163
KEYWORD
nonn
AUTHOR
Robert Price, Jan 02 2016
EXTENSIONS
Removed an unjustified claim that Colin Barker's conjectures are correct. Removed a program based on a conjecture. - N. J. A. Sloane, Jun 13 2022
STATUS
approved