I fiddled around with the problem for a while but no, just find the formula:
[tex]a_n=256\left(\frac{1}{4}\right)^{n-1}[/tex]
The ratio is 1/4 because:
4^4 = 256 = [tex]a_1[/tex]
4^2 = 16 = [tex]a_3[/tex]
First element of sequence: 256
So with these two numbers you can get the formula.
Now plug in 7 for n and solve.
[tex]a_7 = 256( \frac{1}{4})^{7-1} = 256( \frac{1}{4})^{6} = \frac{256}{4096} = \frac{1}{16} [/tex]
