test.php

<?php
$results = [];
for ($i = 0; $i < 100000; $i++) mt_rand();

for ($i = 0; $i < 70000; $i++) {
	do {
		$items = [
			1 => 1,
			2 => 2,
			3 => 3,
			4 => 4,
			5 => 5,
			6 => 6,
			7 => 7,
		];
		while (count($items) > 6) {
			foreach ($items as $key => $item) {
				if (!in_array(mt_rand(1, 6), [ 2, 3, 5 ])) {
					unset($items[$key]);
				}
			}
		}
	}
	while (count($items) == 0);
	
	do { $number = mt_rand(1, 6); }
	while ($number > count($items));
	@$results[$items[array_keys($items)[$number - 1]]]++;
}
ksort($results);
var_dump($results);