Let be a differentiable function satisfying and

MATHEMATICS · Subjective · AoPS · Mathematics · Sequences & Series · Sequences & Series

Problem

Let f(x)f(x) be a differentiable function satisfying f(x)+f(x+12)=1,∀x∈Rf(x) + f\left(x + \frac{1}{2}\right) = 1, \forall x \in \mathbb{R} and g(x)=∫0xf(t)dtg(x) = \int_{0}^{x} f(t) dt. If g(1)=1g(1) = 1, then the value of ∑n=2∞(8∑k=1n(g(x+k2)−g(x+k)))\sum_{n=2}^{\infty} \left( \frac{8}{\sum_{k=1}^{n} (g(x+k^2) - g(x+k))} \right) is.

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