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A069517 a(n) = (-1)*Sum_{d|n} (moebius(d)*(-1)^d). 3
1, 2, 0, 2, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
From Andrew Howroyd, Jul 25 2018: (Start)
Moebius transform of A037227.
Multiplicative because A037227 is. (End)
LINKS
FORMULA
a(1) = 1 and for n>1, a(n) = 2*A209229(n). - corrected by Antti Karttunen, Nov 19 2017
Multiplicative with a(2^e) = 2 and a(p^e) = 0 for an odd prime p. - Amiram Eldar, Aug 29 2023
MATHEMATICA
a[n_] := If[n == 2^IntegerExponent[n, 2], 2, 0]; a[1] = 1; Array[a, 100] (* Amiram Eldar, Aug 29 2023 *)
PROG
(PARI) A069517(n) = (-1)*sumdiv(n, d, moebius(d)*((-1)^d)); \\ Antti Karttunen, Nov 19 2017
(PARI) a(n) = if(n == 1, 1, if(n >> valuation(n, 2) == 1, 2, 0)); \\ Amiram Eldar, Aug 29 2023
CROSSREFS
Sequence in context: A137678 A359893 A218855 * A193526 A160498 A089800
KEYWORD
easy,nonn,mult
AUTHOR
Benoit Cloitre, Apr 16 2002
STATUS
approved

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Last modified March 29 08:08 EDT 2024. Contains 371265 sequences. (Running on oeis4.)