math.CO/0409509 number 37

[rwst]

What is the conjecture

$$ \phi(n^2+1)=n\phi(n+1) \implies n=8 \vee (\text{$(n^2+1)$ is prime and $n+1$ is prime}) $$

(corrected from paper) See https://oeis.org/A067720.

Prerequisites needed

Status: open

Choose either option

• I plan on adding this conjecture to the repository
• This issue is up for grabs: I would like to see this conjecture added by somebody else