%I #9 Aug 21 2024 14:39:03
%S 36,36,54,72,18,36,18,36,36,36,18,36,36,18,18,36,36,54,18,18,90,36,54,
%T 18,18,18,36,18,54,18,36,36,18,18,36,36,18,36,36,18,54,18,72,18,36,54,
%U 18,18,36,18,90,18,36,36,18,18,18,18,18,72,18,36,18,36,18,18,18,18,18,18,36,18,18,18,54,18,18,18,18,18,18
%N First differences of A247678
%C All terms have digital root equal to 9.
%H Odimar Fabeny, <a href="/A247898/b247898.txt">Table of n, a(n) for n = 1..10000</a>
%t Differences[Select[Range[13,3000,18],CompositeQ]] (* _Harvey P. Dale_, Aug 21 2024 *)
%Y Cf. A247678.
%K nonn,easy
%O 1,1
%A _Odimar Fabeny_, Sep 26 2014