# Exponents to math symbols with mathbb

I am using the amsfont package where I can use mathbb to format for instance the symbol for real numbers as follows

$\mathbb{R}$


I want however to include exponents, though my approach so far looks quite terrible:

$\mathbb{R}^{nx1}$


How can this be resolved? Thanks

• Why is this result terrible? What is it that you would want? – gebruiker Apr 1 '18 at 13:02
• It should be \mathbb{R}^{n\times 1} – egreg Apr 1 '18 at 13:04
• @egreg or \mathbb{R}^{n} ? – David Carlisle Apr 1 '18 at 13:40
• @DavidCarlisle That's a notation sometimes used for denoting the n-row, 1-column matrices. – egreg Apr 1 '18 at 13:41
• @egreg yes I guessed that's what it meant (although not a notation I'm familiar with:-) – David Carlisle Apr 1 '18 at 13:42

I guess you want to use \times instead of x (which is always wrong for denoting any kind of multiplication):

\documentclass{article}
\usepackage{amsmath}
\usepackage{amssymb} % or just amsfonts

\begin{document}

Wrong notation: $\mathbb{R}^{nx1}$

Right notation: $\mathbb{R}^{n\times 1}$

\end{document}