A156077 - OEIS

A156077

a(n) = #{1<=k<=n : A000002(k)=1}.

1, 1, 1, 2, 3, 3, 4, 4, 4, 5, 5, 5, 6, 7, 7, 8, 9, 9, 9, 10, 10, 11, 12, 12, 13, 13, 13, 14, 15, 15, 16, 17, 17, 18, 18, 18, 19, 19, 19, 20, 21, 21, 22, 22, 22, 23, 23, 24, 25, 25, 26, 27, 27, 27, 28, 28, 28, 29, 30, 30, 31, 31, 31, 32, 32, 32, 33, 34, 34, 35, 36, 36, 37, 37, 37, 38

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OFFSET

1,4

COMMENTS

A234322(n) = nearest integer to 100*a(n)/n. [Jonathan Sondow, Jan 08 2014]

LINKS

Table of n, a(n) for n=1..76.

O. Bordelles and B. Cloitre, Bounds for the Kolakoski Sequence, J. Integer Sequences, 14 (2011), #11.2.1.

FORMULA

a(n) = n-A074286(n).

a(n) = 2*n - A054353(n). - Jean-Christophe Hervé, Oct 05 2014

MATHEMATICA

a2 = {1, 2, 2}; Do[ a2 = Join[a2, {1 + Mod[n - 1, 2]}], {n, 3, 60}, {i, 1, a2[[n]]}]; a3 = Accumulate[a2]; 2*Range[Length[a3]] - a3 (* Jean-François Alcover, Jun 18 2013 *)

CROSSREFS

Cf. A000002, A234322.

Sequence in context: A046693 A368910 A196376 * A189641 A189672 A058889

Adjacent sequences: A156074 A156075 A156076 * A156078 A156079 A156080

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Feb 03 2009

STATUS

approved