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A026600 a(n) is the n-th letter of the infinite word generated from w(1)=1 inductively by w(n)=JUXTAPOSITION{w(n-1),w'(n-1),w"(n-1)}, where w(k) becomes w'(k) by the cyclic permutation 1->2->3->1 and w"(k) = (w')'(k).

%I A026600 #18 Nov 04 2017 09:50:57
%S A026600 1,2,3,2,3,1,3,1,2,2,3,1,3,1,2,1,2,3,3,1,2,1,2,3,2,3,1,2,3,1,3,1,2,1,
%T A026600 2,3,3,1,2,1,2,3,2,3,1,1,2,3,2,3,1,3,1,2,3,1,2,1,2,3,2,3,1,1,2,3,2,3,
%U A026600 1,3,1,2,2,3,1,3,1,2,1,2,3,2,3,1,3,1,2,1,2,3,3,1,2,1,2,3,2,3,1,1,2,3,2,3,1
%N A026600 a(n) is the n-th letter of the infinite word generated from w(1)=1 inductively by w(n)=JUXTAPOSITION{w(n-1),w'(n-1),w"(n-1)}, where w(k) becomes w'(k) by the cyclic permutation 1->2->3->1 and w"(k) = (w')'(k).
%H A026600 Michael Gilleland, <a href="/selfsimilar.html">Some Self-Similar Integer Sequences</a>
%H A026600 <a href="/index/Fi#FIXEDPOINTS">Index entries for sequences that are fixed points of mappings</a>
%F A026600 a(A026601(n)) = 1.
%F A026600 a(A026602(n)) = 2.
%F A026600 a(A026603(n)) = 3. -_Michael Somos_, Sep 06 2008
%e A026600 1;
%e A026600 (123);
%e A026600 (123)(231)(312);
%e A026600 (123)(231)(312)(231)(312)(123)(312)(123)(231);
%t A026600 Nest[ Flatten[ # /. {1 -> {1, 2, 3}, 2 -> {2, 3, 1}, 3 -> {3, 1, 2}}] &, {1}, 7] (* _Robert G. Wilson v_, Mar 08 2005 *)
%o A026600 (PARI) {a(n) = if( n<2, n>0, (a((n + 2)\ 3) + n + 1 )%3 + 1)} /* _Michael Somos_, Sep 06 2008 */
%Y A026600 Equals A053838(n-1) + 1. Cf. A026601-A026614.
%K A026600 nonn
%O A026600 1,2
%A A026600 _Clark Kimberling_