What does the number outside of the brackets in the Peers column mean?

[lmsuon]

I'm using qbittorrent, what does those numbers outside of the brackets in the Peers column mean? And also in the Seeds column?

[john32123666]

Those nos @ left are the seeds/peers connected to you ...
Those nos @ right inside (bracket) are the nos of swarm ...

Swarm. Together, all peers (including seeds) sharing a torrent are called a swarm. For example, six ordinary peers and two seeds make a swarm of eight.