

A070886


Triangle read by rows giving successive states of cellular automaton generated by "Rule 90".


6



1, 1, 0, 1, 1, 0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0
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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
Index to Elementary Cellular Automata
Index entries for sequences related to cellular automata


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}, rows1]; Flatten[ Table[ca[[k, rowsk+1 ;; rows+k1]], {k, 1, rows}]] (* JeanFrançois Alcover, May 24 2012 *)


CROSSREFS

Cf. A070950, A070887. Alternate rows of A047999. Interpreted as binary numbers: A038183. Interpreted as Zeckendorfexpansions: A048757. Drawn as binary trees: A080263.
Sequence in context: A039966 A089451 A145099 * A041004 A141736 A134842
Adjacent sequences: A070883 A070884 A070885 * A070887 A070888 A070889


KEYWORD

nonn,tabf,nice,easy


AUTHOR

N. J. A. Sloane, May 19 2002


EXTENSIONS

More terms from Hans Havermann, May 26 2002


STATUS

approved



