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A287576 Start with 0 and repeatedly substitute 0->0321, 1->3210, 2->2103, 3->1032. 6

%I

%S 0,3,2,1,1,0,3,2,2,1,0,3,3,2,1,0,3,2,1,0,0,3,2,1,1,0,3,2,2,1,0,3,2,1,

%T 0,3,3,2,1,0,0,3,2,1,1,0,3,2,1,0,3,2,2,1,0,3,3,2,1,0,0,3,2,1,1,0,3,2,

%U 2,1,0,3,3,2,1,0,0,3,2,1,0,3,2,1,1,0

%N Start with 0 and repeatedly substitute 0->0321, 1->3210, 2->2103, 3->1032.

%C This is the fixed point of the morphism 0->0231, 1->2310, 2->3102, 3->1023 starting with 0. Let t be the (nonperiodic) sequence of positions of 0, and likewise, u for 1, v for 2, and w for 3; then t(n)/n -> 4, u(n)/n -> 4, v(n)/n -> 4, w(n)/n -> 4. Also, t(n) + u(n) + v(n) + w(n) = 16*n - 6 for n >= 1. See A287556 for a guide to related sequences.

%H Clark Kimberling, <a href="/A287576/b287576.txt">Table of n, a(n) for n = 1..20000</a>

%H <a href="/index/Fi#FIXEDPOINTS">Index entries for sequences that are fixed points of mappings</a>

%F a(n) = 4n - A287578(n) for n >= 1.

%e First three iterations of the morphism:

%e 0321

%e 0321103221033210

%e 0321103221033210321003211032210321033210032110321032210332100321

%t s = Nest[Flatten[# /. {0 -> {0,3,2,1}, 1 -> {3,2,1,0}, 2 -> {2,1,0,3}, 3 -> {1,0,3,2}}] &, {0}, 9]; (* A287576 *)

%t Flatten[Position[s, 0]]; (* A287577 *)

%t Flatten[Position[s, 1]]; (* A287578 *)

%t Flatten[Position[s, 2]]; (* A287579 *)

%t Flatten[Position[s, 3]]; (* A287580 *)

%Y Cf. A287577, A287578, A287579, A287580.

%K nonn,easy

%O 1,2

%A _Clark Kimberling_, Jun 01 2017

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Last modified April 22 10:38 EDT 2021. Contains 343174 sequences. (Running on oeis4.)