Source: cirosantilli/busy-beaver-function
= Busy beaver function
{tag=Uncomputable function}
{title2=$BB(n)$}
$BB(n)$ is the largest number of 1's written by a <halting problem>[halting] $n$-state <Turing machine> on a tape initially filled with 0's.
\Video[https://www.youtube.com/watch?v=kmAc1nDizu0]
{title=The Boundary of Computation by Mutual Information (2023)}