The return of dupe hunting, pt. 1

[Max Alekseyev]

On 9/24/07, Andrew Plewe <aplewe at sbcglobal.net> wrote:
> I see that now looking at these two sequences, but it's not obvious to
> me from their definitions or the wording that they're supposed to be
> different. Namely, I don't get why the cubes are absent from A022555
> while they're included in A057903.

Note that a cube x^3 is "the sum of 2 nonnegative cubes" since x^3 =
x^3 + 0^3. Hence, the cubes are not in A022555.
On the other hand, a cube x^3 is not "the sum of exactly two positive
cubes" by Fermat Last Theorem (well, by the 3rd degree case of FLT).
Hence, the cubes are in A057903.

Regards,
Max