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%I #6 Jan 07 2021 08:37:20
%S 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,
%T 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,
%U 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
%N a(n) = 1 if the odd part of n is noncomposite, 0 otherwise.
%C 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.
%H Antti Karttunen, <a href="/A340371/b340371.txt">Table of n, a(n) for n = 1..65537</a>
%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%F a(n) = A080339(A000265(n)).
%F For n > 1, a(n) = abs(A304438(n)).
%o (PARI) A340371(n) = (2>bigomega(n>>valuation(n,2)));
%Y Cf. A000265, A080339.
%Y Characteristic function of A093641.
%Y After the initial term, the absolute values of A304438.
%Y Cf. also A340370, A340373.
%Y Differs from A340374 for the first time at n=561, where a(561) = 0.
%K nonn
%O 1
%A _Antti Karttunen_, Jan 06 2021
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