A265172 Binary representation of the n-th iteration of the "Rule 90" elementary cellular automaton starting with a single ON (black) cell.

1, 101, 10001, 1010101, 100000001, 10100000101, 1000100010001, 101010101010101, 10000000000000001, 1010000000000000101, 100010000000000010001, 10101010000000001010101, 1000000010000000100000001, 101000001010000010100000101, 10001000100010001000100010001

Offset: 0

Author

Robert Price, Dec 05 2015

Keywords

• nonn
• easy

Comments

Rules 26, 82, 90, 146, 154, 210 and 218 also generate this sequence.

References

• S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.

Links

• Robert Price, Table of n, a(n) for n = 0..999
• Eric Weisstein's World of Mathematics, Elementary Cellular Automaton
• S. Wolfram, A New Kind of Science
• Index entries for sequences related to cellular automata
• Index to Elementary Cellular Automata

Crossrefs

Cf. A070886.

Programs

Mathematica

rule = 90; rows = 20; Table[FromDigits[Table[Take[CellularAutomaton[rule,{{1},0}, rows-1, {All,All}][[k]], {rows-k+1, rows+k-1}], {k,1,rows}][[k]]], {k,1,rows}]