Question 1087322

I believe you made mistake writing {{{2^(2-1)}}}, should be {{{2^(n-1)}}}

so,
{{{A(n)=-2*2^(n-1 )}}}

Find: 
to find the first term, plug in {{{1}}} for {{{n}}} 
{{{A(1)=-2*2^(1-1 )}}}
{{{A(1)=-2*2^(0 )}}}
{{{A(1)=-2*1 )}}}
{{{A(1)=-2}}}

fourth, {{{n=4}}}

{{{A(4)=-2*2^(4-1 )}}}
{{{A(4)=-2*2^(3 )}}}
{{{A(4)=-2*8 )}}}
{{{A(4)=-16}}}


and eighth term, {{{n=8}}}

{{{A(8)=-2*2^(8-1 )}}}
{{{A(8)=-2*2^(7 )}}}
{{{A(8)=-2*128 )}}}
{{{A(8)=-256}}}


and, your answer is: {{{-2}}}; {{{-16}}};{{{-256}}}