The number above the sum sign is the number of terms in the series, so 5.
The n=1 below the sum sign, means the series starts at 1
Replace n with values from 1 to 5 and then add them together:
4(2)^1 = 8
4(2)^2 = 16
4(2)^3 = 32
4(2)^4 = 64
4(2)^5 = 128
Sum = 8 + 16 + 32 + 64 + 128 = 248
