A156728 a(n) = abs(A054354(n)).

1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1

Offset

1,1

Comments

This sequence is the image of the Kolakoski sequence A000002 under the morphism 1->1, 2->01. [Gabriele Fici, Aug 12 2013]

Links

Table of n, a(n) for n=1..105.

J.M. Fedou and G. Fici, Some remarks on differentiable sequences and recursivity, Journal of Integer Sequences 13(3): Article 10.3.2 (2010). [From Jean-Marc Fedou and Gabriele Fici, Mar 18 2010]

Formula

a(n) = (v(n+1) - v(n) + 1)/2 where v(n) = A156253(n) - A156251(n).

a(n) = (A000002(n) + A000002(n+1)) mod 2.

Mathematica

a2 = {1, 2, 2}; Do[ a2 = Join[a2, {1 + Mod[n - 1, 2]}], {n, 3, 105}, {i, 1, a2[[n]]}]; a[n_] := Mod[a2[[n]] + a2[[n + 1]], 2]; Table[a[n], {n, 1, 105}] (* Jean-François Alcover, Jun 18 2013 *)

Crossrefs

Sequence in context: A285625 A283966 A054354 * A361023 A267442 A267129

Adjacent sequences: A156725 A156726 A156727 * A156729 A156730 A156731

Keyword

nonn

Author

Benoit Cloitre, Feb 14 2009

Status

approved