calculation of the queue

[javaiscrazy]

Hi guys.

I want to calculate the sum of the following queue

(4 * 3^k-1) 6
k=1

K is between 1 - 6
And here’s how I think:

so;
(4 * 3^1-1 ) is 4 * 3^0 = 4 * 0 = 0.
(4 * 3^2-1 ) is 4 * 3 = 12
(4 * 3^3-1 ) is 4 * 9 = 36
(4 * 3^4-1 ) is 4 * 27 = 108
(4 * 3^5-1 ) is 4 * 81 = 364
(4 * 3^6-1 ) is 4 * 243 = 972

And you just calculate these
0+12+36+108+364+972= right?

 

[Mrspi]

Hi guys.

I want to calculate the sum of the following queue

(4 * 3^k-1) 6
k=1

K is between 1 - 6
And here’s how I think:

so;
(4 * 3^1-1 ) is 4 * 3^0 = 4 * 0 = 0.<--------you've got an error here. 3[sup:31mnjxai]0[/sup:31mnjxai] is NOT 0.......
(4 * 3^2-1 ) is 4 * 3 = 12
(4 * 3^3-1 ) is 4 * 9 = 36
(4 * 3^4-1 ) is 4 * 27 = 108
(4 * 3^5-1 ) is 4 * 81 = 364
(4 * 3^6-1 ) is 4 * 243 = 972

And you just calculate these
0+12+36+108+364+972= right?
Well, it WILL be right when you change that "0" to the correct value