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# Arithmetic series formula

The sum of the first n terms in an arithmetic sequence is (n/2)⋅(a₁+aₙ). It is called the

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# Arithmetic series formula

Current time:0:00Total duration:7:47

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The sum of the first n terms in an arithmetic sequence is (n/2)⋅(a₁+aₙ). It is called the **arithmetic series formula**. Learn more about it here. Created by Sal Khan.