A185311 Keränen's abelian squarefree endomorphism of size 85 on the symbols {1,2,3,4}.

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

Offset

1,2

References

V. Keränen. Abelian squares are avoidable on 4 letters. In W. Kuich, editor, Proc. ICALP '92, Lecture Notes in Comp. Sci., 623:4152. Springer-Verlag, Berlin, 1992.

V. Keränen. Mathematica in research of avoidable patterns in strings, In V. Keränen and P. Mitic, editors, Mathematics with Vision, Proc. First International Mathematica Symposium (IMS '95, Southampton, England), 259266. Computational Mechanics Publications, 1995.

V. Keränen. The avoidability of regularities in strings (in Finnish). Arkhimedes, 47(1):7179, 1995.

V. Keränen. On abelian repetition-free words. In V. Demidov, editor, Proc. IAS '96, 814. Murmansk State Pedagogical Institute, Murmansk, 1996.

V. Keränen. Repetition-free strings and computer algebra (in Finnish). In C. Gefwert and P. Orponen and J. Seppänen, editors, Logic, Mathematics and the Computer, Proc. Finnish Artificial Intelligence Society, 14:250257. Hakapaino, Helsinki, 1996.

T. Laakso, Musical rendering of an infinite repetition-free string. In C. Gefwert and P. Orponen and J. Seppänen, editors, Logic, Mathematics and the Computer, Proc. Finnish Artificial Intelligence Society, 14:292-297. Hakapaino, Helsinki, 1996.

Links

Table of n, a(n) for n=1..85.

Arturo Carpi, On the number of abelian square-free words on four letters, Discrete Appl. Math. 81 (1998), no. 1-3, 155-167.

V. Keränen, New Abelian Square-Free DT0L-Languages over 4 Letters

Crossrefs

Cf. A007413, A185312.

Sequence in context: A181974 A322589 A185312 * A338764 A214582 A362502

Adjacent sequences: A185308 A185309 A185310 * A185312 A185313 A185314

Keyword

nonn,fini,full

Author

N. J. A. Sloane, Jan 25 2012

Status

approved