title: LESS mix-in for nth-child?
body: <p>I'm trying to make a LESS mixin that will give me this output:</p>
  
  <pre><code>.resource:nth-child(8n+1) { clear: left; }
  </code></pre>
  
  <p>I've got this so far:</p>
  
  <pre><code>.wrap-every(@n) {
      &amp;:nth-child(@n + "n+1") {  // parse error on this line
          clear: left;
      }
  }
  
  .resource {
      .wrap-every(8);
  }
  </code></pre>
  
  <p>But it's giving a parse error on the indicated line</p>
  
  <blockquote>
    <p><strong>ParseError: Unrecognised input</strong></p>
  </blockquote>
  
  <p>Is there a way to do this?</p>