recursion cannot get this right
<p>We have triangle made of blocks. The topmost row has 1 block, the next row down has 2 blocks, the next row has 3 blocks, and so on. Compute recursively (no loops or multiplication) the total number of blocks in such a triangle with the given number of rows. </p>

<pre><code>triangle(0) → 0
triangle(1) → 1
triangle(2) → 3
</code></pre>

<p>This is my code:</p>

<pre><code>public int triangle(int rows) {
  int n = 0;

  if (rows == 0) {
    return n;
  } else {
    n = n + rows;
    triangle(rows - 1);
  }
}
</code></pre>
