On sequences of Toeplitz matrices over finite fields
For each non-negative integer $n$ let $\mathcal{A}_n$ be an $n+1$ by $n+1$ Toeplitz matrix over a finite field, $F$, and suppose for each $n$ that $\mathcal{A}_n$ is embedded in the upper left corner of $\mathcal{A}_{n+1}$. We study the structure of the sequence $ν= \{ν_n :n \in \mathbb{Z}^+\}$, where $ν_n = \text{null}(\mathcal{A}_n)$ is the nullity of $\mathcal{A}_{n}$. For each $n\in \mathbb{Z}^+$ and each nullity pattern $ν_0,ν_1,\dots,ν_n$, we count the number of strings of Toeplitz matrices $\mathcal{A}_0,\mathcal{A}_1,\dots,\mathcal{A}_{n}$ with this pattern. As an application we present an elementary proof of a result of D. E. Daykin on the number of $n\times n$ Toeplitz matrices over $GF(2)$ of any specified rank. (This is a corrected version of the paper published in Linear Algebra and Its Applications $561$ \, $(2019), 63-80$.) 2000 MSC Classification 15A33, 15A57