Iodine and oxygen can form several different compounds, depending on the ratio of iodine to oxygen atoms. Here are the most common ones:

* Iodine monoxide (I₂O): This is a very unstable compound and difficult to isolate.

* Iodine dioxide (IO₂): Also unstable and difficult to isolate, this compound is a yellow solid.

* Iodine pentoxide (I₂O₅): This is a white solid, a strong oxidizing agent, and the most stable iodine oxide. It's used to determine carbon monoxide concentrations.

So, there's no single compound formula for iodine and oxygen. It depends on the specific oxide you are interested in.