Squares which are 4 Less than Cubes

Theorem

The only two square numbers which are $4$ less than a cube are:

$2^2 + 4 = 2^3$
$11^2 + 4 = 5^3$


Proof


This theorem requires a proof.
You can help $\mathsf{Pr} \infty \mathsf{fWiki}$ by crafting such a proof.
To discuss this page in more detail, feel free to use the talk page.
When this work has been completed, you may remove this instance of {{ProofWanted}} from the code.
If you would welcome a second opinion as to whether your work is correct, add a call to {{Proofread}} the page.



Historical Note

Pierre de Fermat correctly conjectured that there are only two square numbers which are $4$ less than a cube.


Sources

  • 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $121$
  • 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $121$