A107335 - OEIS

%I #3 Mar 30 2012 17:34:15

%S 1,1,3,2,3,1,1,1,3,2,3,1,1,3,1,1,1,3,2,3,1,1,1,3,2,3,1,1,1,3,2,3,1,1,

%T 3,1,1,1,3,2,3,1,1,1,3,2,3,1,1,1,1,3,2,3,1,1,1,3,2,3,1,1,1,3,2,3,1,1,

%U 3,1,1,1,3,2,3,1,1,1,3,2,3,1,1,1,3,2,3,1,1,3,1,1,1,3,2,3,1,1,1,3,2,3,1,1,1

%N Count down Pisot cubic substitution with characteristic polynomial:x^3-3*x^2-2*x-1.

%C x^3-D[x^3+x^2+x+1,x]=:x^3-3*x^2-1*x-1 (x-1)*(x^3+x^2+x+1)=x^4-1

%F 1->{1, 3, 2, 3, 1}, 2->{3}, 3->{1}

%t s[1] = {1, 1, 3, 2, 3, 1}; s[2] = {3}; s[3] = {1}; t[a_] := Flatten[s /@ a]; p[0] = {1}; p[1] = t[p[0]]; p[n_] := t[p[n - 1]] aa = p[4]

%K nonn,uned

%O 0,3

%A _Roger L. Bagula_, May 22 2005