\documentclass[a4paper,10pt]{report}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}

% Title Page
\title{Test tex4ht}
\author{Chris Horler}


\begin{document}
\maketitle

\chapter{DummyCh}

number sourced from Elementary Number Theory / RSA-nnn
\[
\begin{array}{l}
1881988129206079638386972394616504398071635633794173827007\\
6335642298885971523466548531906060650474304531738801130339\\
6716199692321205734031879550656996221305168759307650257059
\end{array}
\]

\end{document}          
