How can one adjust each text to the center for each box of the table?

Here is the example:

\begin{tabularx}{\textwidth}{ |X|X|X|X|X| }
\hline
Equation & 2 & 3 & 5 & 7 \\
\hline
$y_0 = b^{t}$ & -483061 & 1 & -174089 & 793599 \\
\hline
$y_1 = y_0^{2}$ & -1 &  & 73782 & 77096 \\
\hline
\end{tabularx}


I tried \centerline between letters and \center after \textwidth, but it doesn't seem to work.

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Welcome to TeX.sx! A tip: If you indent lines by 4 spaces, they'll be marked as a code sample. You can also highlight the code and click the "code" button (with "{}" on it). – egreg May 5 '13 at 18:12
Thank you for letting me know this! It's my first time here, so I don't have much experience here as I do in Math Stack Exchange. Hopefully, I won't forget. ;) – NasuSama May 5 '13 at 18:15

You should add >{\centering} before the relevant column, or more conveniently define a new column type as follows:

\documentclass{article}

\usepackage{tabularx}

\newcolumntype{Z}{>{\centering\arraybackslash}X}

\begin{document}

\begin{tabularx}{\textwidth}{ |Z|Z|Z|Z|Z|Z| }
\hline
Equation & 2 & 3 & 5 & 7 \\
\hline
$y_0 = b^{t}$ & -483061 & 1 & -174089 & 793599 \\
\hline
$y_1 = y_0^{2}$ & -1 &  & 73782 & 77096 \\
\hline
\end{tabularx}

\end{document}

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Good answer. ;) Thank you very much! – NasuSama May 5 '13 at 18:46