a mystery cleared up: duplicate A-numbers

[N. J. A. Sloane]

When you take A-numbers from the dispenser, I use email
to pass that information to the main program on my home machine.

It turns out that we are using a "spam assassin" program which
can take 4 or more minutes to process email.

So If I do an update of the OEIS within 4 or 5 minutes of
your taking a bunch of A-numbers, the fact that your A-numbers
were taken would not be known to the external machine.


This explains why quite often different people get the same A-numbers from the 
dispenser.

It doesn't happen often, but even once a week is a nuisance.

Moral:  cut down on how many times you use the dispenser, by grabbing 
a larger bunch of A-nums.  And if you have some stale A-numbers,
check they are still unused before using them.

Neil