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A110240
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Decimal form of binary integers produced by a black cell at n-th generation following Wolfram's Rule 30 cellular automata.
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1
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1, 7, 25, 111, 401, 1783, 6409, 28479, 102849, 456263, 1641433, 7287855, 26332369, 116815671, 420186569, 1865727615, 6741246849, 29904391303, 107568396185, 477630335215, 1725755276049, 7655529137527, 27537575631497
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OFFSET
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1,2
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COMMENTS
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Same definition as A074890 but different sequence. Why?
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LINKS
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Table of n, a(n) for n=1..23.
Eric Weisstein's World of Mathematics, Rule 30.
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EXAMPLE
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a(1)=1 because the automate begins at first "generation" with one black cell: 1;
a(2)=5 because one black cell, through Rule 30 at 2nd generation, produces three contiguous black cells: 111 (binary), so 7 (decimal);
a(3)=25 because the third generation is "black black white white black" cells: 11001, so 25 (decimal).
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MATHEMATICA
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rows = 23; ca = CellularAutomaton[30, {{1}, 0}, rows-1]; Table[ FromDigits[ ca[[k, rows-k+1 ;; rows+k-1]], 2], {k, 1, rows}](* Jean-François Alcover, Jun 07 2012 *)
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CROSSREFS
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Cf. A070950, A051023, A092539, A092540, A070952, A100053, A100054, A100055, A094603, A094604, A000225, 074890.
Sequence in context: A102900 A155271 A200152 * A199893 A129791 A216688
Adjacent sequences: A110237 A110238 A110239 * A110241 A110242 A110243
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KEYWORD
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easy,nonn
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AUTHOR
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Alexandre Wajnberg & Eric Angelini, Sep 06 2005
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EXTENSIONS
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More terms from Eric W. Weisstein, Apr 08 2006
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STATUS
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approved
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