63, plus one for the -l, gives me 64:

perl -le'print" ",$,=$",@_=(0..9,A..F);print$_."0:",map chr$a++,@_ for@_'

Update: Welp, it's pretty trivial to trim a character off that, making it 63:

perl -le'print$,=$",$,,@_=(0..9,A..F);print$_."0:",map chr$a++,@_ for@_'

blokhead