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%I #12 Aug 06 2023 03:05:07
%S 1,1,0,1,1,1,1,1,0,1,1,1,1,1,0,1,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0,1,
%T 1,1,1,1,0,1,1,1,0,1,1,1,1,1,1,1,0,1,1,1,1,1,0,1,1,1,1,1,0,1,1,1,1,1,
%U 1,1,0,1,1,1,0,1,1,1,1,1,1,1,0,1,1,1,1,1,0,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0,1,1,1,1,1,0,1,1,1,1,1,1,1,0,1,1
%N (0,1) sequence whose zero positions are indexed by twice the odious numbers given by A091855.
%C 0's appear at positions indexed by 2*A091855(n).
%H Antti Karttunen, <a href="/A127254/b127254.txt">Table of n, a(n) for n = 0..65537</a>
%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>.
%t a[n_] := If[EvenQ[n] && EvenQ[IntegerExponent[n/2, 2]] && OddQ[DigitCount[n/2, 2, 1]], 0, 1]; Array[a, 100, 0] (* _Amiram Eldar_, Aug 06 2023 *)
%o (PARI) A127254(n) = if(n%2,1,!(hammingweight(n)%2 && !(valuation(n/2, 2)%2))); \\ After PARI-code in A091855. - _Antti Karttunen_, Nov 02 2018
%Y Row sums of A127253.
%Y Cf. A000069, A091855.
%K nonn,base
%O 0,1
%A _Paul Barry_, Jan 10 2007
%E More terms from _Antti Karttunen_, Nov 02 2018