What is the value of this equation in the image ?

For i=1 > 4*(1/2)^(1-1)=4*(1/2)^(0)=4*(1)=4
for i=2 > 4*(1/2)^(2-1)=4*(1/2)^(1)=4*(1/2)=2
for i=3 > 4*(1/2)^(3-1)=4*(1/2)^(2)=4*(1/4)=1
total=4+2+1=7

the answer is
the value of this equation in the image is 7

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