OFFSET
0
COMMENTS
Row n has length 2n+1.
This sequence is also generated by Rule 35.
LINKS
Robert Price, Table of n, a(n) for n = 0..9999
Eric Weisstein's World of Mathematics, Elementary Cellular Automaton
Stephen Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.
EXAMPLE
The first ten rows:
1
1 0 0
0 0 0 1 0
1 1 1 1 0 0 1
0 0 0 0 0 0 1 0 0
1 1 1 1 1 1 1 0 0 1 1
0 0 0 0 0 0 0 0 0 1 0 0 0
1 1 1 1 1 1 1 1 1 1 0 0 1 1 1
0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0
1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1
MATHEMATICA
rule = 3; rows = 20; Flatten[Table[Take[CellularAutomaton[rule, {{1}, 0}, rows-1, {All, All}][[k]], {rows - k + 1, rows + k - 1}], {k, 1, rows}]]
CROSSREFS
KEYWORD
nonn,tabf,easy
AUTHOR
Robert Price, Dec 20 2015
STATUS
approved