%N Largest integer k such that k | Phi(k) - d(k) + n, or 0 if no such k exists, where d() is the number of divisors.
%C In the case of n = 3, the condition is satisfied for all the primes.
%e for a(2), 12 | [ Phi(12) + d(12) + 2 ].
%Y Cf. A020488.
%A _Robert G. Wilson v_, Jul 03 2000