%I #4 Mar 30 2012 17:34:15
%S 1,2,1,2,1,2,2,3,1,2,1,2,3,1,2,1,2,1,2,2,3,1,2,1,2,3,1,2,1,2,1,2,2,3,
%T 1,2,1,2,3,2,3,1,2,1,2,3,1,2,1,2,3,1,2,1,1,2,1,2,1,2,2,3,1,2,1,2,3,1,
%U 2,1,2,1,2,2,3,1,2,1,2,3,1,2,1,2,3,1,2,1,1,2,1,2,1,2,2,3,1,2,1,2,3,1,2,1,2
%N Three-symbol substitution: characteristic polynomial: x^3-x^2-3*x-3.
%F 1->{2, 3}, 2->{1, 2, 1}, 3->{2, 1, 2}
%t s[1] = {2, 3}; s[2] = {1, 2, 1}; s[3] = {2, 1, 2}; t[a_] := Flatten[s /@ a]; p[0] = {1}; p[1] = t[p[0]]; p[n_] := t[p[n - 1]] aa = p[6]
%K nonn,uned
%O 0,2
%A _Roger L. Bagula_, May 13 2005