A139074 or 0 if no such prime exists.

[franktaw at netscape.net]

I disagree.  The definition of the sequence should not depend upon the
state of our knowledge.

Instead, a comment should be added to note that the 0's in the sequence
are conjectured.

Franklin T. Adams-Watters

-----Original Message-----
From: drew at math.mit.edu

While I am not as pessimistic as Artur on the Fermat primes question 
(or
maybe I just hope for a long life :)), I agree that this is a better
definition.

Drew

On Apr 22 2008, Artur wrote:

>Dear Neil,

>Proof that such prime in A139074 doesn't exist will be as difficult as
>proof that set of Fermat Primes is complete, and surely we don't see
>these proof for our life. Mayby will be better to say  0 if we don't
>know yet such prime.

>Best wishes
>Artur