Where are the 40s?

This is a new one on me.

I've heard of hotels eliminating certain floors for whatever reason. Example: Many hotels still don't have a 13th floor, skipping from 12 to 14 for superstitious reasons. Their philosophy, I guess, is "Why take chances?"

But I've never been in a hotel that eliminated a whole series of floors until I stayed recently at the Wynn Resort in Las Vegas.

One of the first things I noticed when I got into the elevator to go up to the 52nd floor was that floors 40 through 49 were missing. And it's not as though they were there and the elevator skipped them entirely. The floor-indicator went smoothly from 39 to 50, confirming that the 40s were missing.

I wonder why that is? Yeah, I know, I should have asked someone.

So all I can do is speculate. Does it have something to do with the Chinese superstition that the number "4" is unlucky? I dunno. Anybody have a better answer?