login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A266624
Binary representation of the middle column of the "Rule 45" elementary cellular automaton starting with a single ON (black) cell.
1
1, 11, 111, 1110, 11100, 111001, 1110011, 11100110, 111001100, 1110011001, 11100110010, 111001100101, 1110011001011, 11100110010111, 111001100101110, 1110011001011101, 11100110010111011, 111001100101110110, 1110011001011101101, 11100110010111011011
OFFSET
0,2
REFERENCES
S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.
MATHEMATICA
rule=45; 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 *) mc=Table[catri[[k]][[k]], {k, 1, rows}]; (* Keep only middle cell from each row *) Table[FromDigits[Take[mc, k]], {k, 1, rows}] (* Binary Representation of Middle Column *)
CROSSREFS
Cf. A266619.
Sequence in context: A284399 A284540 A110437 * A266790 A266592 A267209
KEYWORD
nonn,easy
AUTHOR
Robert Price, Jan 01 2016
STATUS
approved