83864055domain: NAppears in sequencesNumbers n such that tau(n) = tau(n+1) and phi(n) = phi(n+1).at n=23A217773Numbers n such that phi(n) + d(n) = phi(n+1) + d(n+1), where phi(n) is the Euler totient function of n and d(n) the number of divisors of n.at n=32A259496