OFFSET

1,1

COMMENTS

a(n) - a(n-1) is in {1,2,3} for n>=2, and a(n)/n -> (12 + 3*sqrt(2))/7.

LINKS

Clark Kimberling, Table of n, a(n) for n = 1..10000

EXAMPLE

As a word, A286801 = 11011001011011001011011..., in which 0 is in positions 3,6,7,9,12,...

MATHEMATICA

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

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

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

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

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

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

CROSSREFS

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling, May 16 2017

STATUS

approved