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A165560
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The arithmetic derivative of n, modulo 2.
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0
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0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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FORMULA
| a(n)= A003415(n) mod 2.
a(n)=(1-(-1)^n’)/2
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MAPLE
| with(numtheory);
P:=proc(i)
local f, n, p, pfs;
for n from 0 by 1 to i do
pfs:=ifactors(n)[2]; f:=n*add(op(2, p)/op(1, p), p=pfs);
print(1/2*(1-(-1)^f));
od;
end:
P(1000);
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CROSSREFS
| Sequence in context: A181712 A126564 A180433 * A014306 A138150 A073089
Adjacent sequences: A165557 A165558 A165559 * A165561 A165562 A165563
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KEYWORD
| easy,nonn
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AUTHOR
| Paolo P. Lava & Giorgio Balzarotti (paoloplava(AT)gmail.com), Sep 24 2009
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EXTENSIONS
| Entries checked by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 07 2009
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