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Several years ago (4-5?), I read a story online that I believe was still being actively being published in a serial format.
The principle idea, as I recall, was that an artificial intelligence determined that it could essentially prevent people from dying altogether by suffusing everything with nanomachines (or something to that effect). The end result was that, years after the fact, a group of people made a sport of trying to kill themselves in increasingly inventive ways, with an ultimate goal of finding a loophole that allows them to die before the AI can prevent it. I think one of the main characters was the oldest woman on Earth prior to everyone becoming immortal, but that may be a different story.
I can't recall what the name of it was, and every attempt to google anything with 'AI' in the search just gives a bunch of current news articles. Thanks for the help!