Question

Find the sum of the first n terms if the series:3+7+13+21+31

Answer 1

Let $$S=0+3+7+13+21+31+.......+a_{n-1}+a_n$$ $$S=3+7+13+21+31+...+a_{n-2}+a_{n-1}+a_n$$

Subtracting the above two equations, we have:

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Below is the implementation of the above approach: