A080814 Successive words in the formal D0L language that produces the Thue-Morse sequence A001285 (start with 1, map 1 -> 12, 2 -> 21).

1, 12, 1221, 12212112, 1221211221121221, 12212112211212212112122112212112, 1221211221121221211212211221211221121221122121121221211221121221

Offset: 1

Author

N. J. A. Sloane, Mar 26 2003

Keywords

• nonn

References

• A. Salomaa, Jewels of Formal Language Theory. Computer Science Press, Rockville, MD, 1981, p. 5.

Links

• Jarosław Grytczuk, Thue type problems for graphs, points and numbers, Discrete Math., 308 (2008), 4419-4429.

Crossrefs

Cf. A001285 (which is the limiting word), A010060, A080815.

Programs

Mathematica

Map[FromDigits,SubstitutionSystem[{1->{1,2},2->{2,1}},{1},7]] (* Paolo Xausa, Dec 24 2023 *)