Current max is one million.
Source:
for ($i = $n1; $i <= $n2; $i++)
{
if($i % 2 != 1) continue;
$v = 3;
$n = sqrt($i);
while ($i % $v != 0 && $v < $n) $v += 2;
if((($i % $v == 0 && $i != $v) * 1) == 0) echo $i.' ';
}
Output:
Page generated in 0.000 seconds.