{ "id": "2102.01018", "version": "v1", "published": "2021-02-01T17:48:45.000Z", "updated": "2021-02-01T17:48:45.000Z", "title": "Gaps in the Thue--Morse word", "authors": [ "Lukas Spiegelhofer" ], "comment": "13 pages", "categories": [ "math.CO", "math.NT" ], "abstract": "The Thue--Morse sequence is a prototypical automatic sequence found in diverse areas of mathematics, and in computer science. We study occurrences of factors $w$ within this sequence, more precisely the sequence of gaps between consecutive occurrences. This sequence is substitutive; we prove that it is not automatic as soon as the length of $w$ is greater than $1$, thereby answering a question by J.~Shallit in the affirmative.", "revisions": [ { "version": "v1", "updated": "2021-02-01T17:48:45.000Z" } ], "analyses": { "subjects": [ "68Q45", "68R15", "11A63" ], "keywords": [ "thue-morse word", "prototypical automatic sequence", "thue-morse sequence", "diverse areas", "computer science" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable" } } }