What is the sum of the first six terms of the series?

We have  a geometric series  where  the common ratio, r , =  -1/4

The sum of the  first six terms is given  by

first term *  [ 1 - r^6 ] / [ 1 - r ] = 

40  [ 1 - (-1/4)^6 ] /  [ 1 - - 1/4]  =

40  [ 1 - ( 1/4096)]  / [ 5/4]  =

(4 * 40) [ 4096 - 1] / [ 5 * 4096 ]  =

160 *  4095  / [ 20480 ] = 

655200 / 20840   =

4095 / 128