Put in the correct equation (i.e. 2*pi). If you put in 20*pi all you are doing is propagating an outdated methodology. As suggested, add a note next to it explaining why it differs to the literature equation.
Then if your boss says it's wrong, explain it to him. If he still tells you it's wrong, tell him that he obviously hasn't noticed that the engineering revolution is already here, and incompetent old fools like him will be the first up against the wall. I bet he won't even know what to say!