I know the name of the first couple base n number systems. But what comes after that? Or do they simply not have a name anymore (other than "base n")?
binary (base 2)
ternary (base 3)
quaternary (base 4)
quinary (base 5)
senary (base 6)
septenary (base 7)
octal (base 8)
nonary (base 9)
decimal (base 10)
undecimal (base 11)
duodecimal (base 12)
tridecimal (base 13)
tetradecimal (base 14)
pentadecimal (base 15)
hexadecimal (base 16)
You could keep going on with the Latin prefixes, and there are a few more beyond what you have written on this website.
In practice if you're working beyond the common base systems, I think most mathematicians would appreciate you saying "base $n$" rather than some long complicated word whose prefix you have to parse.