%I #4 Apr 24 2017 10:32:55
%S 1,4,7,9,12,15,18,21,23,26,29,31,34,37,40,43,45,48,51,53,56,59,61,64,
%T 67,69,72,75,78,81,83,86,89,91,94,97,100,103,105,108,111,113,116,119,
%U 122,125,127,130,133,135,138,141,144,147,149,152,155,157,160,163
%N Positions of 1 in A285208; complement of A285209.
%C Conjecture: 0 < n*r - a(n) < 3, where r = 1 + sqrt(3).
%H Clark Kimberling, <a href="/A285210/b285210.txt">Table of n, a(n) for n = 1..10000</a>
%e As a word, A285205 = 1001001010..., in which 1 is in positions 1,4,7,9,12,...
%t s = Nest[Flatten[# /. {0 -> {1, 0}, 1 -> {0, 1, 0, 0}}] &, {0}, 11]; (* A285208 *)
%t Flatten[Position[s, 0]]; (* A285209 *)
%t Flatten[Position[s, 1]]; (* A285210 *)
%Y Cf. A285205, A285208, A285209.
%K nonn,easy
%O 1,2
%A _Clark Kimberling_, Apr 23 2017