facebook_2605022302888011.php

<?php

$list_arr = array(
	array('numero' => 1),
	array('numero' => 2),
	array('numero' => 3),
	array('numero' => 5),
	array('numero' => 6),
	array('numero' => 8),
	array('numero' => 9),
	array('numero' => 10)
);

$new_list_arr = array();
$missing_number = array();

foreach ($list_arr as $key => $value) {
	array_push($new_list_arr, $value['numero']);
}

foreach ($new_list_arr as $key => $value) {
	if(!in_array($value+1, $new_list_arr)){
		array_push($missing_number, $value+1);
	}
}

array_pop($missing_number);

foreach ($missing_number as $key => $value) {
	array_push($list_arr, ['numero' => $value]);
}

var_dump($list_arr);