In this MWE, it is expected to get seven circles equally spaced in the angular direction with stretching radius. However, I got this weird output.
\documentclass[border=2pt]{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\foreach[count=\i] \x in {0,1,...,6}{%
\pgfmathtruncatemacro\ml{1.2^(\i-1)}
\draw (1,1)++(\x*30:5*\ml) circle[radius=1];
}
\end{tikzpicture}
\end{document}