Why limit your entropy like that? I just use pwgen:
> pwgen -s 64 1 | xsel -b
aepei5hooNu2Zaic6EQueeCiish7eighaibahwaejohchaizo0zei0eiwongaeza
> pwgen -s 64 1 | xsel -b
aepei5hooNu2Zaic6EQueeCiish7eighaibahwaejohchaizo0zei0eiwongaeza
That's a cool alternative though, thanks.