\documentclass{article}
\usepackage{amsmath} % pkg required by EasyLatex
\usepackage{amsfonts} % pkg required by EasyLatex
\usepackage{amssymb} % pkg required by EasyLatex
\usepackage{psfrag} % pkg required by EasyLatex
\usepackage[dvips]{graphicx} % pkg required by EasyLatex

\begin{document}

\{1,2,3$\}^4$

\end{document}