English

Some new congruences on biregular overpartitions

Number Theory 2025-08-06 v2

Abstract

Recently, Nadji, Ahmia and Ram\'{i}rez \cite{Nadji2025} investigate the arithmetic properties of Bˉ1,2(n){\bar B}_{\ell_1,\ell_2}(n), the number of overpartitions where no part is divisible by 1\ell_1 or 2\ell_2 with gcd(1,2)\gcd(\ell_1,\ell_2)=1=1 and 1\ell_1,2\ell_2>1>1. Specifically, they established congruences modulo 33 and powers of 22 for the pairs of (1,2)(\ell_1,\ell_2)\in{(4,3),(4,9),(8,3),(8,9)}\{(4,3),(4,9),(8,3),(8,9)\}, using the concept of generating functions, dissection formulas and Smoot's implementation of Radu's Ramanujan-Kolberg algorithm. After that, Alanazi, Munagi and Saikia \cite{Alanazi2024} studied and found some congruences for the pairs of (1,2){(2,3),(4,3),(2,5),(3,5),(4,9),(8,27),(16,81)}(\ell_1,\ell_2)\in\{(2,3),(4,3),(2,5),(3,5),(4,9),(8,27),\\(16,81)\} using the theory of modular forms and Radu's algorithm. Recently Paudel, Sellers and Wang \cite{Paudel2025} extended several of their results and established infinitely many families of new congruences. In this paper, we find infinitely many families of congruences modulo 33 and powers of 22 for the pairs (1,2)(\ell_1,\ell_2) \in {(2,9),(5,2),(5,4),(8,3)}\{(2,9),(5,2),(5,4),(8,3)\} and in general for (5,2t) (5,2^t) t3\forall t\geq3 and for (3,2t) (3,2^t),(4,3t) (4,3^t) t2\forall t\geq2, using the theory of Hecke eigenform, an identity due to Newman and the concept of dissection formulas and generating functions.

Keywords

Cite

@article{arxiv.2507.01529,
  title  = {Some new congruences on biregular overpartitions},
  author = {N. K. Meher},
  journal= {arXiv preprint arXiv:2507.01529},
  year   = {2025}
}

Comments

This is the first draft of the paper. Any comments are welcome

R2 v1 2026-07-01T03:42:56.202Z