



1, 2, 4, 5, 8, 9, 12, 13, 15, 16, 19, 20, 23, 24, 26, 27, 30, 31, 34, 35, 38, 39, 41, 42, 45, 46, 49, 50, 52, 53, 56, 57, 60, 61, 64, 65, 67, 68, 71, 72, 75, 76, 78, 79, 82, 83, 86, 87, 89, 90, 93, 94, 97, 98, 101, 102, 104, 105, 108, 109, 112, 113, 115, 116
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OFFSET

1,2


COMMENTS

a(n)  a(n1) is in {1,2,3} for n>=2, and a(n)/n > (6 + sqrt(2))/4.


LINKS

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


EXAMPLE

As a word, A286804 = 0010011001100100110011..., in which 0 is in positions 1,2,4,5,8,9,...


MATHEMATICA

s = Nest[Flatten[# /. {0 > {0, 0, 1}, 1 > {0}}] &, {0}, 16]; (* Pell word, A171588 *)
w = StringJoin[Map[ToString, s]];
w1 = StringReplace[w, {"000" > ""}];
st = ToCharacterCode[w1]  48 ; (* A286804 *)
Flatten[Position[st, 0]]; (* A286805 *)
Flatten[Position[st, 1]]; (* A286806 *)


CROSSREFS

Cf. A171588, A286804, A286806.
Sequence in context: A067366 A211967 A099628 * A188072 A296058 A189205
Adjacent sequences: A286802 A286803 A286804 * A286806 A286807 A286808


KEYWORD

nonn,easy


AUTHOR

Clark Kimberling, May 16 2017


STATUS

approved



