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A268272
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Negabinary evil numbers (see comment).
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6
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0, 2, 5, 7, 8, 10, 13, 14, 17, 19, 20, 22, 25, 27, 28, 31, 32, 34, 37, 39, 40, 42, 45, 46, 49, 51, 52, 55, 56, 58, 61, 62, 65, 67, 68, 70, 73, 75, 76, 79, 80, 82, 85, 87, 88, 90, 93, 94, 97, 99, 100, 102, 105, 107, 108, 111, 112, 114, 117, 118, 121, 123, 124
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OFFSET
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0,2
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COMMENTS
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Recall that a number n >= 0 is defined as an evil number (A001969) if its binary expansion contains an even number of 1's, or such n that Thue-Morse sequence A010060(n)=0.
Sequence A269027 is essentially Thue-Morse sequence in "negabinary", i.e., in base -2. So a number n for which A269027(n)=0 it is natural to call "negabinary evil".
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LINKS
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MATHEMATICA
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b = 2; Select[Range[0, 125], Function[k, EvenQ@ Total@ Rest@ Reverse@ Mod[NestWhileList[(# - Mod[#, b])/-b &, k, # != 0 &], b]]] (* Michael De Vlieger, Mar 03 2016, after Robert Lozyniak at A039724 *)
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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