How can I reproduce this table with thick lines?

Question

I'm trying to reproduce this table:

(apologies for the terrible cameraphone pic)

I don't know how to get the slightly thicker leftmost and topmost line.

Here's a minimal example of what I have so far:

\documentclass[a4paper,12pt]{article}

\begin{document}

\begin{tabular}{c|c|c|c|c|c}
    $*$ & $a$ & $b$ & $c$ & $d$ & $e$ \\\hline
    $a$ & $a$ & $b$ & $c$ & $b$ & $d$ \\\hline
    $b$ & $b$ & $c$ & $a$ & $e$ & $c$ \\\hline
    $c$ & $c$ & $a$ & $b$ & $b$ & $a$ \\\hline
    $d$ & $b$ & $e$ & $b$ & $e$ & $d$ \\\hline
    $e$ & $d$ & $b$ & $a$ & $d$ & $c$
\end{tabular}

\end{document}

Is there an easy way to make the leftmost and topmost lines thicker?

Answer 1

You could define a thick version of \hline and a thick | as new column type as I did below. Both are based on the original code, only the thickness got changed from \arrayrulewidth to 1pt.

\documentclass[a4paper,png]{standalone}
\usepackage{array}

\makeatletter
\newcommand{\thickhline}{%
    \noalign {\ifnum 0=`}\fi \hrule height 1pt
    \futurelet \reserved@a \@xhline
}
\newcolumntype{"}{@{\hskip\tabcolsep\vrule width 1pt\hskip\tabcolsep}}
\makeatother


\begin{document}

\begin{tabular}{c"c|c|c|c|c}
    $*$ & $a$ & $b$ & $c$ & $d$ & $e$ \\\thickhline
    $a$ & $a$ & $b$ & $c$ & $b$ & $d$ \\\hline
    $b$ & $b$ & $c$ & $a$ & $e$ & $c$ \\\hline
    $c$ & $c$ & $a$ & $b$ & $b$ & $a$ \\\hline
    $d$ & $b$ & $e$ & $b$ & $e$ & $d$ \\\hline
    $e$ & $d$ & $b$ & $a$ & $d$ & $c$
\end{tabular}

\end{document}

Answer 2

The package tabu provides such a modification by the optional arguments of the vertical line and the command \tabucline

\documentclass[a4paper,12pt]{article}
\usepackage{tabu}
\begin{document}

\begin{tabu}{c|[2pt]c|c|c|c|c}
    $*$ & $a$ & $b$ & $c$ & $d$ & $e$ \\\tabucline[2pt]{-}
    $a$ & $a$ & $b$ & $c$ & $b$ & $d$ \\\hline
    $b$ & $b$ & $c$ & $a$ & $e$ & $c$ \\\hline
    $c$ & $c$ & $a$ & $b$ & $b$ & $a$ \\\hline
    $d$ & $b$ & $e$ & $b$ & $e$ & $d$ \\\hline
    $e$ & $d$ & $b$ & $a$ & $d$ & $c$
\end{tabu}

\end{document}

However to produce nice tables avoid vertical lines and be spare with horizontal lines. For all this I recommend the package booktabs. Via google you will find a lot of examples.