# Inspired by the oldest problem on brilliant

Number Theory Level 5

$A=\sum _{n=1}^{\infty }\frac{\left(-1\right)^nd\left(n\right)}{n^2}$

Find $$\left\lfloor 10000A \right\rfloor$$

Note: $$d(n)$$ denotes the number of positive integer divisors of $$n$$.

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