is then summed with a "PIN offset" stored on the card itself, modulo 10, to
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。pg电子官网对此有专业解读
We can push further left by finding the note whose overtone series contains F. That would be B-flat at 1/9 Hz. Its third harmonic is F at 1/3 Hz, and its fifth harmonic is D at 5/9 Hz. And now we have a new problem: this D clashes with our existing D at 9 Hz.
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