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Define the "Fibonacci" morphism f: 1->12, 2->1 and let a(0) = 2; then a(n+1) = f(a(n)).
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%I #17 Sep 09 2016 08:47:10

%S 2,1,12,121,12112,12112121,1211212112112,121121211211212112121,

%T 1211212112112121121211211212112112,

%U 1211212112112121121211211212112112121121211211212112121

%N Define the "Fibonacci" morphism f: 1->12, 2->1 and let a(0) = 2; then a(n+1) = f(a(n)).

%C a(n) converges to the Fibonacci word A003842.

%C a(n) has length Fibonacci(n+1) (cf. A000045).

%D Berstel, Jean. "Fibonacci words—a survey." In The book of L, pp. 13-27. Springer Berlin Heidelberg, 1986.

%D E. Bombieri and J. Taylor, Which distribution of matter diffracts? An initial investigation, in International Workshop on Aperiodic Crystals (Les Houches, 1986), J. de Physique, Colloq. C3, 47 (1986), C3-19 to C3-28.

%H N. J. A. Sloane, <a href="/A106750/b106750.txt">Table of n, a(n) for n = 0..15</a>

%t FromDigits /@ NestList[ Flatten[ # /. {1 -> {1, 2}, 2 -> 1}] &, {2}, 8] (* _Robert G. Wilson v_, May 17 2005 *)

%Y Cf. A106748, A106749, A003842, A000045, A213975, A213976.

%K nonn

%O 0,1

%A _N. J. A. Sloane_, May 16 2005. Initial term 2 added by _N. J. A. Sloane_, Jul 05 2012

%E More terms from _Robert G. Wilson v_, May 17 2005