Let the growth rate of the first day be a 1, an = 2 * (n- 1) and A 1 to the power of (n- 1).

The eighth day is 2*(8- 1)a 1.

According to the meaning of the question, the sum of the first eight items is equal to 1 and S8= 1.

According to the summation formula of proportional sequence, sn = a1(1-q * n)/(1-q), and q = 2.

Get a 1= 1/255, S6=2 1/85.