%I #10 Oct 02 2016 10:17:23
%S 2,2,1,2,2,2,2,1,2,2,1,1,4,4,3,4,4,1,1,2,2,1,2,2,2,2,1,2,2,2,2,1,2,2,
%T 2,2,1,2,2,1,1,4,4,3,4,4,1,1,2,2,1,2,2,2,2,1,2,2,1,1,4,4,3,4,4,1,1,1,
%U 1,4,4,3,4,4,1,1,4,4,3,4,4,4,4,3,4,4,3,3,2,2,1,2,2,3,3,4,4,3,4
%N Trajectory of 1 under the morphism 1->{2,2,1,2,2}, 2->{3}, 3->{4,4,3,4,4}, 4->{1}.
%C Pentasilver dragon 5-symbol substitution, characteristic polynomial x^4-2*x^3+x-16.
%C The existence of the three polynomials silver: x^4-2*x^3+x^2-4, double silver: x^4-4x^3+4x^2-4 and pentasilver: x^4-2*x^3+x-16 confirms that a Kenyon-like polynomial of a general form: x^4-p*x^3+q*x^2-r exists with substitutions associated to it.
%H <a href="/index/Fi#FIXEDPOINTS">Index entries for sequences that are fixed points of mappings</a>
%t s[1] = {2, 2, 1, 2, 2}; s[2] = {3}; s[3] = {4, 4, 3, 4, 4}; s[4] = {1}; t[a_] := Flatten[s /@ a]; p[0] = {1}; p[1] = t[p[0]]; p[n_] := t[p[n - 1]] aa = p[5]
%K nonn
%O 0,1
%A _Roger L. Bagula_, May 06 2005
%E Corrected and edited by _N. J. A. Sloane_, Jun 03 2005