A102394 - OEIS

%I #5 Aug 02 2020 02:29:18

%S 0,2,3,0,5,0,0,8,9,0,0,12,0,14,15,0,17,0,0,20,0,22,23,0,0,26,27,0,29,

%T 0,0,32,33,0,0,36,0,38,39,0,0,42,43,0,45,0,0,48,0,50,51,0,53,0,0,56,

%U 57,0,0,60,0,62,63,0,65,0,0,68,0,70,71,0,0,74,75,0,77,0,0,80,0,82,83,0,85,0

%N A wicked odious sequence.

%C Odious numbers plus one (A000069(n)+1) appear at positions indexed by the odious numbers, 0 otherwise. A000027(n) = A102393(n) + A102394(n).

%F a(n) = (n+1)(1-(-1)^A000120(n))/2.

%F a(n) = (n+1)(1-(-1)^A010060(n))/2.

%t a[n_] := If[OddQ @ DigitCount[n, 2, 1], n + 1, 0]; Array[a, 100, 0] (* _Amiram Eldar_, Aug 02 2020 *)

%Y Cf. A000027, A000069, A000120, A010060, A102392, A102393.

%K easy,nonn

%O 0,2

%A _Paul Barry_, Jan 06 2005