{ "id": "2209.01639", "version": "v1", "published": "2022-09-04T15:22:12.000Z", "updated": "2022-09-04T15:22:12.000Z", "title": "Arithmetic properties of certain $t$-regular partitions", "authors": [ "Rupam Barman", "Ajit Singh", "Gurinder Singh" ], "comment": "17 pages", "categories": [ "math.NT" ], "abstract": "For a positive integer $t\\geq 2$, let $b_{t}(n)$ denote the number of $t$-regular partitions of a nonnegative integer $n$. Motivated by some recent conjectures of Keith and Zanello, we establish infinite families of congruences modulo $2$ for $b_9(n)$ and $b_{19}(n)$. We prove some specific cases of two conjectures of Keith and Zanello on self-similarities of $b_9(n)$ and $b_{19}(n)$ modulo $2$. We also relate $b_{t}(n)$ to the ordinary partition function, and prove that $b_{t}(n)$ satisfies the Ramanujan's famous congruences for some infinite families of $t$. For $t\\in \\{6,10,14,15,18,20,22,26,27,28\\}$, Keith and Zanello conjectured that there are no integers $A>0$ and $B\\geq 0$ for which $b_t(An+ B)\\equiv 0\\pmod 2$ for all $n\\geq 0$. We prove that, for any $t\\geq 2$ and prime $\\ell$, there are infinitely many arithmetic progressions $An+B$ for which $\\sum_{n=0}^{\\infty}b_t(An+B)q^n\\not\\equiv0 \\pmod{\\ell}$. Next, we obtain quantitative estimates for the distributions of $b_{6}(n), b_{10}(n)$ and $b_{14}(n)$ modulo 2. We further study the odd densities of certain infinite families of eta-quotients related to the 7-regular and $13$-regular partition functions.", "revisions": [ { "version": "v1", "updated": "2022-09-04T15:22:12.000Z" } ], "analyses": { "keywords": [ "arithmetic properties", "ordinary partition function", "regular partition functions", "establish infinite families", "congruences modulo" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }