login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

{1010->2}-transform of the infinite Fibonacci word A003849.
4

%I #8 Jul 27 2024 04:51:16

%S 0,1,0,0,2,0,1,0,0,2,0,2,0,1,0,0,2,0,1,0,0,2,0,2,0,1,0,0,2,0,2,0,1,0,

%T 0,2,0,1,0,0,2,0,2,0,1,0,0,2,0,1,0,0,2,0,2,0,1,0,0,2,0,2,0,1,0,0,2,0,

%U 1,0,0,2,0,2,0,1,0,0,2,0,2,0,1,0,0,2

%N {1010->2}-transform of the infinite Fibonacci word A003849.

%H Clark Kimberling, <a href="/A285680/b285680.txt">Table of n, a(n) for n = 1..10000</a>

%e As a word, A003849 = 01001010010010100..., and replacing each 1010 by 2 gives 01002010020201002010020201002020100201...

%t s = Nest[Flatten[# /. {0 -> {0, 1}, 1 -> {0}}] &, {0}, 13] ; (* A003849 *)

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

%t w1 = StringReplace[w, {"1010" -> "2"}]

%t st = ToCharacterCode[w1] - 48; (* A285680 *)

%t Flatten[Position[st, 0]]; (* A285681 *)

%t Flatten[Position[st, 1]]; (* A285682 *)

%t Flatten[Position[st, 2]]; (* A285683 *)

%Y Cf. A003849, A285677, A285681, A285682, A285683.

%K nonn,easy

%O 1,5

%A _Clark Kimberling_, May 11 2017