We present rapidly converging series for tile Khintchine constant and
for general ''Khintchine means'' of continued. fractions, We show that
each of these constants can be cast in terms of an efficient free-par
ameter series, each series involving values of the Riemann zeta functi
on, rationals, and logarithms of rationals. We provide an alternative,
polylogarithm series for the Khintchine constant and indicate means t
o accelerate such series. We discuss properties of some explicit conti
nued fractions, constructing specific fractions that have limiting geo
metric mean equal to the Khintchine constant. We report numerical eval
uations of such special numbers and of various Khintchine means. In pa
rticular, we used an optimized series and a collection of fast algorit
hms to evaluate the Khintchine constant to more than 7000 decimal plac
es.