A102392 - OEIS

%I #13 Nov 23 2023 12:27:54

%S 0,1,2,0,4,0,0,7,8,0,0,11,0,13,14,0,16,0,0,19,0,21,22,0,0,25,26,0,28,

%T 0,0,31,32,0,0,35,0,37,38,0,0,41,42,0,44,0,0,47,0,49,50,0,52,0,0,55,

%U 56,0,0,59,0,61,62,0,64,0,0,67,0,69,70,0,0,73,74,0,76,0,0,79,0,81,82,0,84,0

%N Odious numbers in odious places.

%C Odious numbers A000069(n) appear at positions indexed by the odious numbers, 0 otherwise. A001477(n)=A102391(n)+A102392(n).

%H Harvey P. Dale, <a href="/A102392/b102392.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n)=if((1+floor(n/2))(1+(-1)^A000120(n))/2=0, n, 0); a(n)=if((1+floor(n/2))(1+(-1)^A010060(n))/2=0, n, 0).

%t odnQ[n_]:=OddQ[DigitCount[n,2,1]]; Table[If[odnQ[n],n,0],{n,0,100}] (* _Harvey P. Dale_, Oct 15 2019 *)

%o (Python)

%o def A102392(n): return n*(n.bit_count()&1) # _Chai Wah Wu_, Nov 23 2023

%K easy,nonn,base

%O 0,3

%A _Paul Barry_, Jan 06 2005