How to have correct page numbering with twoside=false in PDF (produced from bookdown)?

Question

I have simple bookdown document:

---
title: Page number problem
documentclass: book

site: bookdown::bookdown_site
output:
  bookdown::pdf_book: default

papersize: a4
geometry: 'left=0.8in, right=0.4in, top=0.5in, bottom=1in, twoside=false'

header-includes:
- \usepackage[fontsize=14pt]{scrextend}
- \pagestyle{plain}

---

# Header 1

Some text on page 2 

\newpage

# Header 2

Some text on page 3

I expect the following page numbering:

1. title (not numbered)
2. contents (numbered)
3. chapter 1 (numbered)
4. chapter 2 (numbered)

but got two No 1 pages:

What am I doing wrong or missed?

Answer 1

This is standard behavior of the LaTeX book and report classes, though I cannot point you to the relevant documentation right now. For onside documents the titlepage is treated like an un-numbered cover page. If you want to start the actual page numbering at 2, you can add \stepcounter{page} before the TOC. One way to achieve this would be to add

include-before:
- \stepcounter{page}

to your YAML header.