



1, 2, 4, 5, 7, 8, 9, 10, 12, 13, 15, 16, 18, 19, 21, 22, 23, 24, 26, 27, 29, 30, 31, 32, 34, 35, 37, 38, 40, 41, 43, 44, 45, 46, 48, 49, 51, 52, 53, 54, 56, 57, 59, 60, 61, 62, 64, 65, 67, 68, 69, 70, 72, 73, 75, 76, 78, 79, 81, 82, 83, 84, 86, 87, 89, 90
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OFFSET

1,2


COMMENTS

Conjecture: 2 < n*r  a(n) < 2 for n>=1, where r = (1 + sqrt(3))2.


LINKS

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


EXAMPLE

As a word, A285421 = 110110111101..., in which 1 is in positions 1,2,4,5,7,...


MATHEMATICA

s = Nest[Flatten[# /. {0 > {1, 1}, 1 > {0, 1, 1}}] &, {0}, 11] (* A285421 *)
Flatten[Position[s, 0]] (* A285422 *)
Flatten[Position[s, 1]] (* A285423 *)


CROSSREFS

Cf. A285419, A285421, A285422.
Sequence in context: A047498 A026367 A039069 * A173025 A203463 A223909
Adjacent sequences: A285420 A285421 A285422 * A285424 A285425 A285426


KEYWORD

nonn,easy


AUTHOR

Clark Kimberling, Apr 28 2017


STATUS

approved



