A106559 Peano-like substitution of four symbols that gives a narrow strip with a hole in it: characteristic polynomial:x^4-x^3-4x^2-x-15.

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

Offset

0,1

Comments

The digraph of this substitution has an asymmetrical sink in it.

Links

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

F. M. Dekking, Recurrent Sets, Advances in Mathematics, vol. 44, no.1, April 1982, page 85, section 4.1

Formula

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

Mathematica

s[1] = {2, 3, 2}; s[2] = {3, 1, 3}; s[3] = {4, 2, 4}; s[4] = {1, 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

Sequence in context: A334014 A280929 A231725 * A280047 A106377 A214573

Adjacent sequences: A106556 A106557 A106558 * A106560 A106561 A106562

Keyword

nonn,uned

Author

Roger L. Bagula, May 09 2005

Status

approved