I have found this quite challenging!Quote:

For any prime , if , prove that .

I thought maybe we could divide it into two cases, where and .

If we consider Euler's function , then we have, for ,

.

Since , then

.

So we could say that

and .

And we can say a bunch of other things, too, none of which seem to get me closer to a solution.

Any help would be much appreciated!