%N Positive integers n such that S(n) divides n, where S(n) is the sum of the iterates of the Euler phi-function of n, that is, S(n) = phi(n)+phi(phi(n))+....+ 1.
%D Igor E. Shparlinski, On the sum of iterations of the Euler function, Journal of Integer Sequences, Volume 9 (2006), Article 06.1.6.
%e 18 is in the sequence because phi(18)+phi(phi(18))+phi(phi(phi(18))) = 6 + 2 + 1 = 9, which divides 18.
%Y Cf. A082897.
%A __Jeffrey Shallit__, Jan 22 2006