A286937 - OEIS

%I #8 May 20 2017 22:49:34

%S 1,1,0,1,1,0,0,1,1,0,0,1,1,0,1,1,0,0,1,1,0,0,1,1,0,1,1,0,0,1,1,0,0,1,

%T 1,0,0,1,1,0,1,1,0,0,1,1,0,0,1,1,0,1,1,0,0,1,1,0,0,1,1,0,0,1,1,0,1,1,

%U 0,0,1,1,0,0,1,1,0,1,1,0,0,1,1,0,0,1

%N {111->null}-transform of the Sturmian word A080764.

%C A080764 = 1101101110110111011011011101..., and removing each 111 gives

%C 110110011001101100110011..., in which the positions of 0 are given by A286938, and of 1, by A286939.

%H Clark Kimberling, <a href="/A286937/b286937.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = 1 - A286804(n) for n >= 1.

%t s = Nest[Flatten[# /. {0 -> 1, 1 -> {1, 1, 0}}] &, {1}, 7] (* A080764 *)

%t w = StringJoin[Map[ToString, s]]

%t w1 = StringReplace[w, {"111" -> ""}]

%t st = ToCharacterCode[w1] - 48 ; (* A286937 *)

%t Flatten[Position[st, 0]];  (* A286806 *)

%t Flatten[Position[st, 1]];  (* A286805 *)

%Y Cf. A080764, A286805, A286806.

%K nonn,easy

%O 1

%A _Clark Kimberling_, May 17 2017