%I #4 Apr 21 2017 08:06:43
%S 3,5,9,11,13,15,19,21,25,27,29,31,35,37,41,43,47,49,53,55,57,59,63,65,
%T 69,71,73,75,79,81,85,87,89,91,95,97,101,103,105,107,111,113,117,119,
%U 123,125,129,131,133,135,139,141,145,147,149,151,155,157,161
%N Positions of 1 in A285139; complement of A285140.
%C Conjecture: -1 < n*r - a(n) < 1 for n>=1, where r = 1 + sqrt(3).
%H Clark Kimberling, <a href="/A285141/b285141.txt">Table of n, a(n) for n = 1..10000</a>
%e As a word, A285139 = 001010..., in which 1 is in positions 3,5,9,11,,...
%t s = Nest[Flatten[# /. {0 -> {1, 0}, 1 -> {0, 0, 1, 0}}] &, {0}, 12]; (* A285139 *)
%t Flatten[Position[s, 0]]; (* A285140 *)
%t Flatten[Position[s, 1]]; (* A285141 *)
%Y Cf. A285139, A285140, A285142.
%K nonn,easy
%O 1,1
%A _Clark Kimberling_, Apr 20 2017