2,4,8,16,32,64,128…… How to express the nth number of this group of numbers? Good answer plus points (correct question)

2,4,8,16,32,64,128…… How to express the nth number of this group of numbers? Good answer plus points (correct question)

This is an equal ratio sequence, the common ratio is 2, the prime minister is 2, so an = n power of 2