Hi there...where n is the number of senses. For humans, there are 2^5 - 1 = 31 formats.
Humans have 5 basics senses: sight, hearing, taste, smell and touch.
If we think at file formats that we can interact, are using only a part of them. In general, files are divided as: text, images, waves and movies (moving images with sound).
With text and images we are using only sight; with movies we are using sight and hearing.
Let's see how many formats can exist for our senses. We basically all senses apart, all senses grouped in 2, in 3, in 4 and all together. The formula for this is:
Now, we only know 4 of them!!!
What's the next one? :)