A286801 - OEIS

%I #5 May 17 2017 11:33:55

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

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

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

%N {0->110, 1->010}-transform of the Pell word, A171588.

%C A171588 = 001001000100100010010010001001..., and replacing each 0 by 110 and each 1 by 010 gives 1101100101101100101101101100101..., in which the positions of 0 are given by A286802, and of 1, by A286803.

%H Clark Kimberling, <a href="/A286801/b286801.txt">Table of n, a(n) for n = 1..10000</a>

%t s = Nest[Flatten[# /. {0 -> {0, 0, 1}, 1 -> {0}}] &, {0}, 16]; (* Pell word, A171588 *)

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

%t w1 = StringReplace[w, {"0" -> "110", "1" -> "010"}];

%t st = ToCharacterCode[w1] - 48 ; (* A286801 *)

%t Flatten[Position[st, 0]];  (* A286802 *)

%t Flatten[Position[st, 1]];  (* A286803 *)

%Y Cf. A171588, A286802, A286803.

%K nonn,easy

%O 1

%A _Clark Kimberling_, May 16 2017