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A267058
Decimal representation of the n-th iteration of the "Rule 97" elementary cellular automaton starting with a single ON (black) cell.
2
1, 0, 20, 19, 256, 255, 5120, 5119, 65536, 65535, 1310720, 1310719, 16777216, 16777215, 335544320, 335544319, 4294967296, 4294967295, 85899345920, 85899345919, 1099511627776, 1099511627775, 21990232555520, 21990232555519, 281474976710656, 281474976710655
OFFSET
0,3
REFERENCES
S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.
FORMULA
Conjectures from Colin Barker, Jan 10 2016 and Apr 19 2019: (Start)
a(n) = a(n-2)+256*a(n-4)-256*a(n-6) for n>5.
G.f.: (1+19*x^2+19*x^3-20*x^4+236*x^5) / ((1-x)*(1+x)*(1-4*x)*(1+4*x)*(1+16*x^2)).
(End)
Conjecture: a(n) = 256^floor(n/4)*(((n-1)/2 + 1) mod 2) + 20*256^floor(n/4)*(((n-1)/2) mod 2) - 1 for odd n; a(n) = 256^floor(n/4)*((n/2 + 1) mod 2) + 20*256^floor(n/4)*((n/2) mod 2) for even n. - Karl V. Keller, Jr., Jul 03 2022
MATHEMATICA
rule=97; 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: A023462 A261307 A172164 * A205545 A087708 A220022
KEYWORD
nonn,easy
AUTHOR
Robert Price, Jan 09 2016
STATUS
approved