It's possible - a one node configuration file demonstrates this. Why would you not want an odd number - probably because even numbers are more pleasing? You'll configure different files according to processing needs.
Kenneth Bland
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The number of nodes should actually be 2 or more when configuring your APT file. When you configure a job during development/testing with a single node, there is no parallel testing done.
This can cause some issues when deploying from a 1 node system to a multi-node system.