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A153881
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1 followed by -1, -1, -1, ... .
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30
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1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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a(1) = 1; a(n) = -1, n > 1.
a(n) = 1 - 2*sign(n-1) = 1 - 2*A057427(n-1).
a(n) = (-1)^sign(1-n) = (-1)^A057427(1-n).
a(n) = 2*floor(1/n)-1 = 2*A063524(n)-1. (End)
Dirichlet g.f.: 2 - zeta(s). - Álvar Ibeas, Dec 30 2018
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MAPLE
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MATHEMATICA
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PROG
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CROSSREFS
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If prefixed by initial 0, we get A134824.
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KEYWORD
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sign,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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