SOLUTION: Find the smallest n such that the sum of 1 + 3 + 3^2 + 3^3 + ...3^n exceeds 1,000,000.

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Question 1080327: Find the smallest n such that the sum of 1 + 3 + 3^2 + 3^3 + ...3^n exceeds 1,000,000.
Answer by ikleyn(52805) About Me  (Show Source):
You can put this solution on YOUR website!
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Using MS Excel

n      3%5En      sum
---------------------

0	1	1
1	3	4
2	9	13
3	27	40
4	81	121
5	243	364
6	729	1093
7	2187	3280
8	6561	9841
9	19683	29524
10	59049	88573
11	177147	265720
12	531441	797161
13	1594323	2391484    <<<---<<< n = 13.

Solved.