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A182581
(3-adic valuation of n), read mod 2.
7
0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1
OFFSET
1
COMMENTS
(a(n)) is the unique fixed point of the morphism 0->001, 1->000. This follows by passing from A145204, which gives the positions of 1 in (a(n)), to its complement A007417, and to A014578. - Michel Dekking, Sep 09 2022
LINKS
Dimitri Hendriks, Frits G. W. Dannenberg, Jörg Endrullis, Mark Dow and Jan Willem Klop, Arithmetic Self-Similarity of Infinite Sequences, arXiv preprint 1201.3786 [math.CO], 2012.
FORMULA
a(n) = A007949(n) mod 2.
Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = 1/4. - Amiram Eldar, Jul 24 2022
MATHEMATICA
Mod[IntegerExponent[Range[105], 3], 2] (* Jean-François Alcover, Sep 15 2018 *)
PROG
(PARI) a(n) = valuation(n, 3) % 2; \\ Michel Marcus, Jul 29 2017
CROSSREFS
Characteristic function of A145204 \ {0}.
Binary complement is (A014578(n+1)).
Sequence in context: A309768 A080887 A099395 * A288203 A238470 A286748
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, May 06 2012
STATUS
approved