%N Positive integers n such that the sum of decimal digits of (16^n-1) is divisible by n.
%C Comparing with A165722 there is one additional term a(8)=9.
%C No other terms below 10^5.
%o (PARI) isok(n) = (sumdigits(16^n-1) % n) == 0; \\ _Michel Marcus_, Oct 16 2013
%Y Cf. A165722.
%A _Zak Seidov_, Sep 25 2009