[seqfan] Re: Fwd: Your A051217 Nonnegative numbers of the form 6^x-y^2.

[David Wilson]

Stop using that terminology.

The sequence is perfectly well-defined.
n >= 0 is in the sequence iff it is of the form 6^x - y^2.
Every n >= 0 is either of this form or it is not.

The question is, is the sequence computable?
Specifically, is there an algorithm that determines if n is in or out of 
the sequence?

The real question is,

On 11/11/2011 9:57 AM, Charles Greathouse wrote:
> No, scratch that.  I can show that the sequence is well-defined
> through ten million.  No general proof yet, though.
>
> Charles Greathouse
> Analyst/Programmer
> Case Western Reserve University