\documentclass{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\foreach[count=\i] \x in {20,18,...,2}\foreach[count=\j] \y in {20,18,...,2}\node at (\i,\j) {\x \y};
\end{tikzpicture}
\end{document}

\node at (\i,\j) {\x \y}; 就是写文本的意思