Project Euler 722 - Slowly converging series

Official link: https://projecteuler.net/problem=722

Note: This problem is not suitable for hints

Thought Process

Note: This problem is not suitable for hints



After some research, I first found the Lambert Series and I got fairly far, but it was too slow, after that I found an extremely useful identity from the Divisor Function page and ended up solving the problem without any programming

Interactive Code

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