Qq overspeed fortune _qq overspeed calculation formula

Because the sequence an = n power of 3-n power of 2

So a 1 = 3-2 = 1.

1/a 1 = 1

When n >; =2

3 n-2 n = (1+2) n-2 n =1+c (1,n) 2+ C(2, n) 2 2+...+c (n-/kloc)

& gt= 2 * 2^(n- 1)

So n & gt=2

3^n-2^n & gt； 2^n

1 Yes /(3 n-2 n)

1/a 1+ 1/a2............+ 1/an

& lt 1/a 1+ 1/2^2 +...+ 1/2^n

= 1+( 1/2^2- 1/2^(n+ 1))/( 1- 1/2)

= 1+( 1/2^2- 1/2^(n+ 1))/( 1/2)

& lt 1 +( 1/2^2 -0)/( 1/2)

= 1+ 1/2

= 3/2