cofr/base keyword usage

[Ralf Stephan]

David,
you are quite right in pointing to the fuzzyness of the cofr keyword
because we simply don't know a formula for the constant expressed by
a continued fraction expansion of a random non-cofr sequence.
So I'm backing away from trying to enforce correct usage.

Regarding base, I'd love to see more expression-awareness, i.e., that
submitters not only use 'base-10 digits' instead of 'digits' but also
that they submit the corresponding base-2 and base-3 sequences first.
Also, as you say, sequences having formulas/recurrences should have
the formula placed in the definition, and the base keyword removed.


ralf