title: Problem 760
date: 2021/06/27 02:00:00
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# [Problem 760](https://projecteuler.net/problem=760)
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[Xem đề gốc (tiếng Anh)](https://projecteuler.net/problem=760)

## **Tổng theo toán tử bit**

$f(n) = \sum_{k=0}^{n} (n \text{ AND } k) + (n \text{ OR } k) + (n \text{ XOR } k)$. Tính $\sum_{n=0}^{10^{18}} f(n) \pmod{10^9+7}$.

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