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A049321
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Primitive Chacon sequence: fixed under 0->0012, 1->12, 2->012.
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3
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0, 0, 1, 2, 0, 0, 1, 2, 1, 2, 0, 1, 2, 0, 0, 1, 2, 0, 0, 1, 2, 1, 2, 0, 1, 2, 1, 2, 0, 1, 2, 0, 0, 1, 2, 1, 2, 0, 1, 2, 0, 0, 1, 2, 0, 0, 1, 2, 1, 2, 0, 1, 2, 0, 0, 1, 2, 0, 0, 1, 2, 1, 2, 0, 1, 2, 1, 2, 0, 1, 2, 0, 0, 1, 2, 1, 2, 0, 1, 2, 1, 2, 0, 1, 2, 0, 0, 1, 2, 1, 2, 0, 1, 2, 0, 0, 1, 2, 0, 0, 1, 2, 1, 2, 0
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,4
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COMMENTS
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This sequence was introduced by Ferenczi in his 1995 paper. It has the property that it maps to the non-primitive Chacon sequence A049320 via the letter-to-letter map 0->0, 1->1, 2->0. See Ferenczi's paper, page 281. - Michel Dekking, Oct 24 2019
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LINKS
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FORMULA
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a(n) = beta(0 A049320(n)), where beta is the 2-block map given by 00->0, 10->2, 01->1. - Michel Dekking, Oct 24 2019
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EXAMPLE
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beta(0001000...) = beta(00)beta(00)beta(01)beta(10)beta(00)beta(00)... = 001200.... - Michel Dekking, Oct 24 2019
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MATHEMATICA
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Nest[Flatten[# /. {0 -> {0, 0, 1, 2}, 1 -> {1, 2}, 2 -> {0, 1, 2}}]&, {0}, 4] (* Jean-François Alcover, Oct 05 2016 *)
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PROG
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(Haskell)
a049321 n = a049321_list !! n
a049321_list = 0 : 0 : 1 : 2 : f [0, 0, 1, 2] where
f xs = drop (length xs) ys ++ f ys where
ys = concatMap ch xs
ch 0 = [0, 0, 1, 2]; ch 1 = [1, 2]; ch 2 = [0, 1, 2]
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CROSSREFS
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KEYWORD
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nonn,nice,easy
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AUTHOR
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EXTENSIONS
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More terms from Larry Reeves (larryr(AT)acm.org), Apr 12 2000
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STATUS
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approved
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