Echo array value

If you just need to have the print_array($var) provide an array of values, then you need to change the database function from $wpdb->get_results to $wpdb->get_var.

You are retrieving just one value from the database, so get_var is the function which will return that specific value directly.

Edit:

You can create a comma separated list from the above array using implode(',', $val) which can later be passed to any other variables.

$values = implode(',', $val);
$result="(" . $values . ')';