[MM3-users] Where in database are subject prefix sequences stored?

I am using numeric prefixes for a list, such that it's [ListName-000012].

Where would that sequence indicator be stored in the database? Postorious' database?  Hyperkitty's database?  I ask because I'm rebuilding a home-grown listserv solution using Mailman3 and the main requirement is the thread IDs being *properly sequential* with the current implementation, so I have to set the "next ID in sequence" to a start value.

I don't see this clearly in the DB where the sequence value would be stored, so if anyone knows that'd be great to know so I can get this working.

Thomas