{ "id": "2107.03556", "version": "v1", "published": "2021-07-08T01:28:14.000Z", "updated": "2021-07-08T01:28:14.000Z", "title": "Some Remarks on Small Values of $τ(n)$", "authors": [ "Kaya Lakein", "Anne Larsen" ], "comment": "8 pages, 2 tables", "categories": [ "math.NT" ], "abstract": "A natural variant of Lehmer's conjecture that the Ramanujan $\\tau$-function never vanishes asks whether, for any given integer $\\alpha$, there exist any $n \\in \\mathbb{Z}^+$ such that $\\tau(n) = \\alpha$. A series of recent papers excludes many integers as possible values of the $\\tau$-function using the theory of primitive divisors of Lucas numbers, computations of integer points on curves, and congruences for $\\tau(n)$. We synthesize these results and methods to prove that if $0 < |\\alpha| < 100$ and $\\alpha \\notin T := \\{2^k, -24,-48, -70,-90, 92, -96\\}$, then $\\tau(n) \\neq \\alpha$ for all $n > 1$. Moreover, if $\\alpha \\in T$ and $\\tau(n) = \\alpha$, then $n$ is square-free with prescribed prime factorization. Finally, we show that a strong form of the Atkin-Serre conjecture implies that $|\\tau(n)| > 100$ for all $n > 2$.", "revisions": [ { "version": "v1", "updated": "2021-07-08T01:28:14.000Z" } ], "analyses": { "subjects": [ "11F30" ], "keywords": [ "small values", "atkin-serre conjecture implies", "vanishes asks", "natural variant", "lehmers conjecture" ], "note": { "typesetting": "TeX", "pages": 8, "language": "en", "license": "arXiv", "status": "editable" } } }