<?php
ini_set('max_execution_time', 300);
echo "start time:" . date("i:s:u") . "<br />";

function isPrime($number,&$prevPrimes){
    foreach ($prevPrimes as $key => $prime)
    {
        if ($prime === 1)
        {
            continue;
        }
        elseif ($number % $prime === 0)
        {
            return 0;
        }
    }
    // If we get to here, $number is prime
    return $number;
}
$primes = array();
$i = 0;
$nbPrimes = 0;
while ($nbPrimes < 10001)
{
    $i++;
    if ($i % 2 != 0)
    {
        $result = isPrime($i, $primes);

        if ($result !== 0)
        {
            $primes[] = $i;
            $nbPrimes++;
        }
    }
}
echo "#$nbPrimes: $result<br>";

echo "End time:" . date("i:s:u") . "<br />";