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%I #14 Nov 17 2018 20:46:02
%S 1,3,6,9,27,90,108,144,243
%N Numbers k such that k divides the sum of digits of 9^k.
%C Next term after 243, if it exists, is greater than 30000. - _Ryan Propper_, Jun 18 2005
%C No more terms < 1000000. - _Lars Blomberg_, May 05 2011
%e 3 divides the sum of digits of 9^3 (i.e., 7 + 2 + 9 = 18), so 3 is a term.
%t Do[If[Mod[Plus @@ IntegerDigits[9^n, 10], n] == 0, Print[n]], {n, 1, 30000}] (* _Ryan Propper_, Jun 18 2005 *)
%t Select[Range[300],Divisible[Total[IntegerDigits[9^#]],#]&] (* _Harvey P. Dale_, Jun 03 2015 *)
%K hard,more,nonn,base
%O 1,2
%A _Amarnath Murthy_ and _Shyam Sunder Gupta_, Feb 16 2002
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