On sums of coefficients of Borwein type polynomials over arithmetic progressions

Abstract

We obtain asymptotic formulas for sums over arithmetic progressions of coefficients of polynomials of the form $$\prod _{j=1}^n\prod _{k=1}^{p-1}(1-q^{pj-k}{)}^s,$$ where $p$ is an odd prime and $n,s$ are positive integers. Let us denote by $a_i$ the coefficient of $q^i$ in the above polynomial and suppose that $b$ is an integer. We prove that $$|\sum _{i\equiv b\text{mod}2pn}{a}_i-\frac{v(b)p^{sn}}{2pn}|\le p^{sn/2},$$ where $v(b)=p-1$ if $b$ divisible by $p$ and $v(b)=-1$ otherwise. This improves a recent result of Goswami and Pantangi.

9 pages. Improved version