[quchen]

Just enumerate them all, if none is missing it's fairly easy to compress. (And 1b per number is really inefficient) ;-)

main = traverse print [1..99999999]

[WJW]

The Kolmogorov complexity of the set of all phone numbers is pretty low. All phone numbers with a few missing is also pretty low.

In fact, I now wonder if you can even compress the 3.8b phone number set to less than 1 bit per phone number. It should be pretty doable since a significant chunk of the number space is not valid.

[dillondoyle]

But not all numbers are valid? 911. Not all area codes exist.

[luckman212]

What language is that?

[WJW]

Haskell