A106688 Six-symbol substitution: characteristic polynomial: x^6 - 4*x^4 - 3*x^3 - x - 1.

2, 4, 2, 5, 6, 3, 4, 3, 6, 1, 4, 5, 2, 4, 2, 5, 6, 2, 4, 1, 4, 5, 2, 2, 5, 6, 3, 6, 3, 4, 2, 5, 6, 3, 4, 3, 6, 1, 4, 5, 3, 4, 2, 5, 6, 2, 2, 5, 6, 3, 6, 3, 4, 3, 4, 3, 6, 1, 4, 5, 2, 4, 1, 4, 5, 2, 4, 2, 5, 6, 3, 4, 3, 6, 1, 4, 5, 2, 4, 2, 5, 6, 2, 4, 1, 4, 5, 2, 2, 5, 6, 3, 6, 2, 4, 2, 5, 6, 3, 4, 3, 6, 1, 4, 5

Offset: 0

Author

Roger L. Bagula, May 13 2005

Keywords

• nonn
• uned

Examples

			[1] -> [2] -> [3,4] -> [2,4,2,5,6] -> [3,4,2,5,6,3,4,3,6,1,4,5] -> ... Lengths of iterates is 1,1,2,5,12,28,... = A034943. - _Michael Somos_
		

Programs

Mathematica

s[1] = {2}; s[2] = {3, 4}; s[3] = {2, 4}; s[4] = {2, 5, 6}; s[5] = {3, 6}; s[6] = {1, 4, 5}; t[a_] := Flatten[s /@ a]; p[0] = {1}; p[1] = t[p[0]]; p[n_] := t[p[n - 1]] aa = p[7]

PARI

{a(n)=my(A); if(n<1,0, A=[2]; while(length(A)Michael Somos, May 16 2005 */

Formula

1->{2}, 2->{3, 4}, 3->{2, 4}, 4->{2, 5, 6}, 5->{3, 6}, 6->{1, 4, 5}