A287443 - OEIS

A287443

Start with 0 and repeatedly substitute 0->012, 1->201, 2->021.

0, 1, 2, 2, 0, 1, 0, 2, 1, 0, 2, 1, 0, 1, 2, 2, 0, 1, 0, 1, 2, 0, 2, 1, 2, 0, 1, 0, 1, 2, 0, 2, 1, 2, 0, 1, 0, 1, 2, 2, 0, 1, 0, 2, 1, 0, 2, 1, 0, 1, 2, 2, 0, 1, 0, 1, 2, 2, 0, 1, 0, 2, 1, 0, 1, 2, 0, 2, 1, 2, 0, 1, 0, 2, 1, 0, 1, 2, 2, 0, 1, 0, 1, 2, 2, 0

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OFFSET

1,3

COMMENTS

This is the fixed point of the morphism 0->012, 1->201, 2->021 starting with 0. Let u be the (nonperiodic) sequence of positions of 0, and likewise, v for 1 and w for 2; then u(n)/n -> 3, v(n)/n -> 3, w(n)/n -> 3.

See A287385 for a guide to related sequences.

LINKS

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

Index entries for sequences that are fixed points of mappings

EXAMPLE

First three iterations of the morphism: 012, 012201021, 012201021021012201012021201.

MATHEMATICA

s = Nest[Flatten[# /. {0->{0, 1, 2}, 1->{2, 0, 1}, 2->{0, 2, 1}}] &, {0}, 9]; (*A287443*)

Flatten[Position[s, 0]]; (*A287444*)

Flatten[Position[s, 1]]; (*A287445*)

Flatten[Position[s, 2]]; (*A287446*)

CROSSREFS