Difference between revisions of "2017 AMC 10A Problems/Problem 1"
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− | Notice this is the term <math>a_6</math> in an arithmetic sequence, | + | Notice this is the term <math>a_6</math> in an arithmetic sequence, defined recursively as <math>a_1 = 3, a_n = 2a_(n-1) + 1.</math> Thus: |
<cmath>\begin{split} | <cmath>\begin{split} | ||
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a_2 = 3*2 + 1 = 7.\\ | a_2 = 3*2 + 1 = 7.\\ | ||
a_3 = 7 *2 + 1 = 15.\\ | a_3 = 7 *2 + 1 = 15.\\ |
Revision as of 14:21, 8 February 2017
Problem
What is the value of ?
Solution
Notice this is the term in an arithmetic sequence, defined recursively as Thus: