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A135585
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a(n) = Sum_{i=1..n} (floor(S2(i)/3) mod 2), where S2(i) = A000120(i).
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2
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0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 3, 4, 5, 5, 5, 5, 6, 6, 7, 8, 9, 9, 10, 11, 12, 13, 14, 15, 16, 16, 16, 16, 17, 17, 18, 19, 20, 20, 21, 22, 23, 24, 25, 26, 27, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 41, 41, 41, 41, 42
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OFFSET
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0,12
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COMMENTS
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Sequence A115384 is a(n) = Sum_{i=1..n} (floor(S2(n)*1/1) mod 2) = Sum_{i=1..n} (S2(n) mod 2).
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LINKS
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MAPLE
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MATHEMATICA
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f[n_] := n - Sum[Floor[n/2^k], {k, 1, Infinity}]; Table[Sum[Mod[Floor[f[i]/3], 2], {i, 1, n}], {n, 0, 25}] (* G. C. Greubel, Oct 20 2016 *)
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PROG
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(PARI) a(n) = sum(i=1, n, hammingweight(i)\3 % 2); \\ Michel Marcus, Sep 19 2015
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CROSSREFS
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KEYWORD
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easy,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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