I need a refresher on how to calculate bacterial growth when the generation time is known. If a cell double every 4 hour then at 8 hours we have 2 cells at16 hours we have 4 at 32 hours 8 etc.

My task is to calculate what the population would be if I am starting with 20 cells , the generation or doubling time is 4 hours and 14 days has elapsed?

Thanks