{ "id": "2301.13563", "version": "v1", "published": "2023-01-31T11:22:01.000Z", "updated": "2023-01-31T11:22:01.000Z", "title": "The Thue-Morse sequence in base 3/2", "authors": [ "Michel Dekking" ], "categories": [ "math.CO" ], "abstract": "We discuss the base 3/2 representation of the natural numbers. We prove that the sum of digits function of the representation is a fixed point of a 2-block substitution on an infinite alphabet, and that this implies that sum of digits function modulo 2 of the representation is a fixed point $x_{3/2}$ of a 2-block substitution on $\\{0,1\\}$. We prove that $x_{3/2}$ is mirror invariant, and present a list of conjectured properties of $x_{3/2}$, which we think will be hard to prove. Finally, we make a comparison with a variant of the base 3/2 representation, and give a general result on $p$-$q$-block substitutions.", "revisions": [ { "version": "v1", "updated": "2023-01-31T11:22:01.000Z" } ], "analyses": { "subjects": [ "11B85", "68R15" ], "keywords": [ "thue-morse sequence", "representation", "fixed point", "digits function modulo", "block substitutions" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }