% Generate plain formulas to be turned into png files via a pdf. Code hints taken
% from:
%
% https://tex.stackexchange.com/questions/287481/using-latex-to-generate-png-images-of-an-equation/287501
%
\documentclass[multi={mymath},border=1pt]{standalone}
% \usepackage{amsmath}
\newenvironment{mymath}{$\displaystyle}{$}

\begin{document}

\begin{mymath}
  F = Fcenter * 2^{(signal * octaves)}
\end{mymath}

\end{document}