In case anyone is still reading this thread, I think four is now proven optimal. Short explanation: https://mobile.twitter.com/zwegner/status/148011092775217561

In case anyone is still reading this thread, I think four is now proven optimal. Short explanation: https://mobile.twitter.com/zwegner/status/1480110927752175618 https://mobile.twitter.com/zwegner/status/148011092775217561... ...and my code: https://gist.github.com/zwegner/508cc183ab94dd27686a40384783ca4e https://gist.github.com/zwegner/508cc183ab94dd27686a40384783...