[Tex/LaTex] Making a larger sum

Question

I have the following code, and the sum sign isn't tall enough, the fraction sticks out from the top and bottom, how do I correct this?

\documentclass[12pt]{article}
\usepackage[a4paper]{geometry}
\usepackage{amsmath}
\begin{document}
$$\sum_{k=n+1}^{\infty} \frac{1}{k!}$$
\end{document}

Thanks in advance.

Answer 1

You may try with the relsize package:

\documentclass[12pt]{article}
\usepackage[a4paper]{geometry}
\usepackage{amsmath}
\usepackage{relsize}

\begin{document}

\[ \sum_{k=n+1}^{\infty} \frac{1}{k!} \]
\[ \mathlarger{\sum}_{k=n+1}^{\infty} \frac{1}{k!} \]

\end{document}