Adjusting the summation sign:

Question

I would like the limits to be vertically above and below the summation sign. I also need a larger summation sign... This is currently what I have:

$x^2sin(x) = \sum_{n=-\infty\atop n\ne \pm 1}^\infty \dfrac {4i(-1)^{n}n}{(n^2 - 1)^2} $

Any help appreciated!

Answer 1

One of this solutions should be suitable for you. Observe that \dfrac requires, e.g., amsmath.

\documentclass{article}

\usepackage{amsmath}
\begin{document}
%$x^2sin(x) = \sum_{n=-\infty\atop n\ne \pm 1}^\infty \dfrac {4i(-1)^{n}n}{(n^2 - 1)^2} $

$x^2\sin(x) = \displaystyle\sum_{n=-\infty\atop n\ne \pm 1}^\infty \dfrac {4i(-1)^{n}n}{(n^2 - 1)^2} $

or

\[
x^2\sin(x) =\sum_{n=-\infty\atop n\ne \pm 1}^\infty \dfrac {4i(-1)^{n}n}{(n^2 - 1)^2}
 \]

\end{document}