Count up, skipping some numbers

The easiest way would be to use an expression on the source text property of a text layer. The math involved depends on how fast you want the counter to go up and which numbers you want to skip. For example if you used this expression you could convert time into frames, then divide the frames by the number of frames you wanted the number to stay the same, then multiply the result by 2. This would give you a count  that was only even numbers -2, 0, 2, 4, 6,  8 and so on. You could then add an if statement to stop the count at 160.

Another option would be to apply Math.Round to the value of a slider and then animate the value of the slider. This will give you whole numbers. You could divide these whole numbers by 2 to give you even numbers or 4 or 3. Then to skip groups of numbers you could add some additional keyframes.

Please give us a detailed explanation of exactly what you are trying to do and we can probably quickly point you to an efficient solution.