  For each integer I, it simply checks
      whether any smaller J evenly divides it.  The total amount of work
      for a given N is thus roughly proportional to 1/2*N^2.
    </p>

    <p>
      Here are the counts of the number of primes for some selected values of N:
      <table border="1" align="center">
        <tr>
          <th>N</th><th>Number of Primes</th>
        </tr>
        <tr>
          <td>1</td><td>0</td>
        </tr>
        <tr>
          <td>10</td><td>4</td>
        </tr>
        <t