# Play with functions 2

Algebra Level 5

If $$f(x)$$ is a function such that $$f(x-1) + f(x+1) = \sqrt{3} f(x)$$ and $$f(5)= 10$$, then what is the sum of digits of $$\displaystyle \sum_{i=0}^{19} f(5 + 12i )$$?

Also try solving Play with functions 3.

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