\documentclass{minimal}
                                                         
\usepackage{amsmath,pst-text}

\DeclareFixedFont{\SF}{T1}{ptm}{b}{ol}{5mm}
                                     
\def\Frac#1#2#3{\tabular{c}$#1$\\[-1.8ex]#2\\[-1.8ex]$#3$\endtabular} 
\def\FFrac#1#2#3{\tabular{c}$#1$\\[-1ex]#2\\[-1ex]$#3$\endtabular} 

\begin{document}
\begin{pspicture}(-4,-4)(4,4) 
  \pstextpath[c]{\psarc[linestyle=none](0,0){2}{150}{390}}%
{$\Frac{\scriptstyle 2\pi i}{\mbox{----}}{\scriptstyle k+2} = -\FFrac{1}{--}{Z}$}

\end{pspicture}
\end{document}