You tell your friend a joke. Your friend tells two more people the joke and each of those two people tells two more people the joke. The number of people who know the punchline to the joke after t tellings can be found using the formula $\displaystyle{P}={{2}}^{{t}}\usepackage{cmbright}\Huge\$ . How many people will know the punchline to the joke after 8 tellings?

The number of people who will know the punchline to the joke is _____.