[Tex/LaTex] KOMA-Script; Hide number of chapter header, but keep it in the ToC and for the sections

Question

I'm using KOMA-Script to write a report. I want the header of the chapters to be unnumbered in the text, but numbered in the ToC. And i also want the sections in this chapter to be numbered as if the chapters were numbered normally. I tried to use \addchap{Introduction}, but it didn't worked the way i wanted to. It removed the number from the Chapter header, but it also lead to the sections be numbered as 0.1/0.2/etc. And it also removed the number in the ToC.

\documentclass[twoside,open=right,12pt,a4paper,abstracton,BCOR=15mm,bibliography=totoc,toc=indentunnumbered]{scrreprt}

\usepackage{lettrine}
\usepackage[normalem]{ulem}
\usepackage{lmodern}
\usepackage{tocloft}

\renewcommand*{\abstractname}{\Large Abstract}
\renewcommand{\contentsname}{\centering Contents}
\renewcommand{\cftpartleader}{\cftdotfill{\cftdotsep}}

\pagenumbering{gobble}

\title{title}
\author{author}

\begin{document}

\maketitle

\begin{abstract}
\noindent
\end{abstract}

\clearpage
\tableofcontents

\addchap{Introduction}  
\pagenumbering{arabic}

\section{Motivation}

\section{Formalism}

\end{document}

This produces a header without number and wrong numbered sections and no number in the ToC. I want the sections to be numbered 1.1/1.2/etc and "1. Introduction" in the ToC but no number in front of the chapter header "Introduction" in the text.

Answer 1

You can redefine \chapterformat:

\documentclass{scrreprt}

\renewcommand*\chapterformat{}

\usepackage{blindtext}% dummy text
\begin{document}
\tableofcontents
\chapter{Introduction}
\blindtext
\section{Motivation}
\Blindtext
\section{Formalism}
\Blindtext
\end{document}