OFFSET
0,1
COMMENTS
If either neighbor is 1 then new state is 1, otherwise new state is 0.
Row n has length 2n+1.
Rules #18, #26, #82, #90, #146, #154, #210, #218 all give rise to this sequence. - Hans Havermann
REFERENCES
S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 25.
LINKS
Robert Price, Table of n, a(n) for n = 0..9999
Eric Weisstein's World of Mathematics, Rule 90
S. Wolfram, A New Kind of Science
EXAMPLE
1; 1,0,1; 1,0,0,0,1; 1,0,1,0,1,0,1; ...
MATHEMATICA
rows = 10; ca = CellularAutomaton[90, {{1}, 0}, rows-1]; Flatten[ Table[ca[[k, rows-k+1 ;; rows+k-1]], {k, 1, rows}]] (* Jean-François Alcover, May 24 2012 *)
CROSSREFS
KEYWORD
nonn,tabf,nice,easy
AUTHOR
N. J. A. Sloane, May 19 2002
EXTENSIONS
More terms from Hans Havermann, May 26 2002
STATUS
approved