<PRE><B>Question 1050725</B>
&lt;pre&gt;&lt;b&gt; 
1, -2, 4, -8,16

1st term = 1 = 2&lt;sup&gt;0&lt;/sup&gt;
2nd term = 2 = 2&lt;sup&gt;1&lt;/sup&gt;
3rd term = 4 = 2&lt;sup&gt;2&lt;/sup&gt;
4th term = 8 = 2&lt;sup&gt;3&lt;/sup&gt;
5th term = 16 = 2&lt;sup&gt;4&lt;/sup&gt;

Notice that the exponent of 2 is 1 less than
the number of term.

nth term = 2&lt;sup&gt;n-1&lt;/sup&gt; ignoring sign.

But then you need the sign-changer factor (-1)&lt;sup&gt;n-1&lt;/sup&gt;.	

nth term = (-1)&lt;sup&gt;n-1&lt;/sup&gt;2&lt;sup&gt;n-1&lt;/sup&gt;

a&lt;sub&gt;n&lt;/sub&gt; = (-1)&lt;sup&gt;n-1&lt;/sup&gt;2&lt;sup&gt;n-1&lt;/sup&gt;


Edwin&lt;/pre&gt;</PRE>