A106644 - OEIS

A106644

A minimal four-symbol substitution with characteristic polynomial x^4-x-1.

4, 2, 3, 3, 1, 3, 1, 1, 4, 3, 1, 1, 4, 1, 4, 4, 2, 3, 1, 1, 4, 1, 4, 4, 2, 1, 4, 4, 2, 4, 2, 3, 3, 1, 1, 4, 1, 4, 4, 2, 1, 4, 4, 2, 4, 2, 3, 1, 4, 4, 2, 4, 2, 3, 4, 2, 3, 3, 1, 3, 1, 1, 4, 1, 4, 4, 2, 1, 4, 4, 2, 4, 2, 3, 1, 4, 4, 2, 4, 2, 3, 4, 2, 3, 3, 1, 1, 4, 4, 2, 4, 2, 3, 4, 2, 3, 3, 1, 4, 2, 3, 3, 1, 3, 1

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,1

COMMENTS

A minimal Pisot like substitution matrix isomer, but in 4 symbols.

LINKS

Table of n, a(n) for n=0..104.

FORMULA

1->{3), 2->{4}, 3->{2, 4}, 4->{1}

MATHEMATICA

s[1] = {3}; s[2] = {4}; s[3] = {4, 2}; s[4] = {1}; t[a_] := Flatten[s /@ a]; p[0] = {1}; p[1] = t[p[0]]; p[n_] := t[p[n - 1]] aa = p[26]

CROSSREFS