Continue previous Roman page numbering after changing to Arabic

Question

what I want to achieve is this continuous numbering with roman numbers:

I, II, III, 1, 2, 3, n, IV, V

But using:

\pagenumbering{Roman} 
\pagenumbering{Arabic}
\pagenumbering{Roman}

Returns this:

I, II, III, 1, 2, 3, n, I, II, III

Help please!

Answer 1

What we do is save the page counter before exiting Roman pages the first time, and reinstate that page counter when (i.e., after) re-entering Roman page numbering later in the document.

\documentclass{article}
\usepackage{lipsum}
\newcounter{savepage}
\begin{document}
\pagenumbering{Roman} 
\lipsum[1-15]

\cleardoublepage
\setcounter{savepage}{\arabic{page}}
\pagenumbering{arabic}
\lipsum[1-20]

\cleardoublepage
\pagenumbering{Roman}
\setcounter{page}{\thesavepage}
\lipsum[1-20]
\end{document}