3. Timestamp Server by Rutger van der Tas

'The solution we propose begins with a timestamp server. A timestamp server works by taking a hash of a block of items to be timestamped and widely publishing the hash, such as in a newspaper or Usenet post [2-5]. The timestamp proves that the data must have existed at the time, obviously, in order to get into the hash. Each timestamp includes the previous timestamp in its hash, forming a chain, with each additional timestamp reinforcing the ones before it.'

Source: https://bitcoin.org/bitcoin.pdf

13 pieces will form the complete collection. 3 can be found as a Legendary Edition in the blueprint 'Looking for Satoshi' on Async.Art

https://async.market/blueprints/63bbe0d4601a6248ac0333a1/rutger-van-der-tas-looking-for-satoshi

The complete collection will be minted during 2023. More info will follow over the course of this year. Follow me on Twitter for up-to-date information, so you know where to look for them.