Sequences whose entries are A-numbers

[Brendan McKay]

I personally find sequences of the form "A-numbers of sequences
such that..." completely useless and a terrible idea.

Sometimes it can be interesting to know whether a particular
sequence is prime-free, or square-free, or whatever.  However,
the A-number of that sequence is an arbitrary label and not
interesting.

There is a solution: invent new flags like "prime-free" and 
attach them to sequences where that property is interesting.

Brendan.