echo  Math::int32(1 - ( Math::int32( $n * int32( Math::int32(Math::int32($n * $n) * 15731) + 789221 ) + 1376312589 ) & 0x7FFFFFFF ) / 1073741824 );
 
class Math
{
    public static function int32($value)
    {
        if ($value < -2147483648)
        {
            return -(-($value) & 0xffffffff);
        }
        elseif ($value > 2147483647)
        {
            return ($value & 0xffffffff);
        }
        return $value;
    }
}