<p>In crontab, I can use an asterisk to mean every value, or "*/2" to mean every even value.</p>

<p>Is there a way to specify every <strong>odd</strong> value? (Would something like "1+*/2" work?)</p>

Try
```
```
1-23/2
```
```
From your question, I'm assuming Vixie Cron.  I doubt this will work with any other cron.