Huh, that's weird. It looks like something got screwed in the copy/paste process, because the previous article I linked definitely has the correct "range/step" format. I thought I had copied it from there, but can't find this example there. And you're absolutely right, the version I quote here is syntactically invalid.

So the syntactically valid version does not work in that earlier cron-to-English translator, but it does appear to work in this version.

My apologies for the error on my part.