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A340371 a(n) = 1 if the odd part of n is noncomposite, 0 otherwise. 3
1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 1, 1, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET
1
COMMENTS
a(n) = 1 if n is of the form 2^i * p^j, for some odd prime p, with i >= 0, 0 <= j <= 1, and 0 otherwise.
LINKS
FORMULA
a(n) = A080339(A000265(n)).
For n > 1, a(n) = abs(A304438(n)).
PROG
(PARI) A340371(n) = (2>bigomega(n>>valuation(n, 2)));
CROSSREFS
Characteristic function of A093641.
After the initial term, the absolute values of A304438.
Cf. also A340370, A340373.
Differs from A340374 for the first time at n=561, where a(561) = 0.
Sequence in context: A334460 A071023 A166280 * A340374 A070887 A209635
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 06 2021
STATUS
approved

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Last modified March 28 14:38 EDT 2024. Contains 371254 sequences. (Running on oeis4.)