# Summation as exponent

 x^{\displaystyle\sum_{k=1}^n {n \choose k}p^k + 1}


How can I make the exponent look smaller?

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\displaystyle is causing the exponent to be over-large. if the reason you're using that is to get the limits above and below the sum, then use \sum\limits instead. but gonzalo's answer is better. – barbara beeton May 16 '14 at 1:35

Instead fo trying to accommodate such a big expression as a superscript, I'd suggest you to use a name for it and then explain this name:

\documentclass{article}
\usepackage{amsmath}

\begin{document}

$x^{\alpha},\quad\text{where } \alpha=\sum_{k=1}^n \binom{n}{k} p^k + 1.$

$x^{\alpha},\text{ where } \alpha=\sum_{k=1}^n \binom{n}{k} p^k + 1$.

\end{document}


Also, \choose is an old command; use \binom{}{} instead.

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Thanks so much, substitution is so much better :D – abe15 May 16 '14 at 1:39

I would probably remove the \displaystyle and enclose it in parentheses, like this:

and then shrink it down even further using \scriptscriptstyle, like this:

which I find plenty readable... although Gonzalo's suggestion of giving it an intermediate name is probably the clearest, unless you're all out of variable names to spare. :)

\documentclass{article}
\usepackage{amsmath}
\begin{document}

$x^{(\sum_{k=1}^n \binom{n}{k} p^k + 1)}$

$x^{(\raisebox{.35pt}{$\scriptscriptstyle{\sum_{k=1}^n \binom{n}{k} p^k + 1}$})}$

\end{document}

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