Este es el código.
<html>
<body style="margin:0px">
<?php
if (isset($_POST['n1'])){
echo "<pre>";
print_r($_POST);
echo "</pre>";
}else{
?><center>
<form method=post enctype="multipart/form-data">
<?php
for ($f=1;$f<=210;$f++){
echo "<input type=text name=n$f size=5 value=".($f*10).">";
echo "\n";
}
?>
<br><br><input type="submit" value=enviar>
</form></center>
<?php }?>
</body>
</html>