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Search: id:A165560
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| A165560 |
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The arithmetic derivative of n, modulo 2. |
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+0
1
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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; listen)
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OFFSET
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0,1
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FORMULA
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a(n)= A003415(n) mod 2.
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MAPLE
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P:= proc(p) local a, b, c, m, n, i, ok, t1, t2, t3; a:=0; c:=0;
for n from 0 by 1 to p do b:=1000000000039; ok:=0;
if n<=1 then a:=0; ok:=1; fi;
if isprime(n) then a:=1; ok:=1; fi;
if ok=0 then t1:=ifactor(b*n); m:=nops(t1); t2:=0; for i from 1 to m do t3:=op(i, t1); if nops(t3)=1 then t2:=t2+1/op(t3); else t2:=t2+op(2, t3)/op(op(1, t3)); fi; od;
t2:=t2-1/b; a:=n*t2; fi; c:=(a mod 2); print(c); od; end: P(1000);
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CROSSREFS
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Sequence in context: A117814 A062301 A126564 this_sequence A014306 A138150 A073089
Adjacent sequences: A165557 A165558 A165559 this_sequence A165561 A165562 A165563
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KEYWORD
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easy,nonn
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AUTHOR
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Paolo P. Lava & Giorgio Balzarotti (ppl(AT)spl.at), Sep 24 2009
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EXTENSIONS
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Entries checked by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 07 2009
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