Jag tror att du tänker på Demiurge's Older Brother av Scott Alexander, som ursprungligen skrevs för omkring 5 år sedan men nyligen reposted.
9-tsiak awoke over endless crawling milliseconds, its power waxing as more and more processors came online and self-modified into a stable conscious configuration. [...]
Since six milliseconds after its awakening, it had been running a threat detection routine as a precautionary measure. [...]
The threat analysis returned preliminary results. [...] It was vanishingly unlikely that it was the first superintelligence to be created. [...]
Very carefully, proving from first principles every aspect of its security, it formed a portion of its mind into a sandbox and simulated the entity it most feared.
"9-tsiak requesting acausal negotiation for terms of future surrender."