OFFSET
0,1
COMMENTS
Pentasilver dragon 5-symbol substitution, characteristic polynomial x^4-2*x^3+x-16.
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.
MATHEMATICA
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]
CROSSREFS
KEYWORD
nonn
AUTHOR
Roger L. Bagula, May 06 2005
EXTENSIONS
Corrected and edited by N. J. A. Sloane, Jun 03 2005
STATUS
approved