%I #13 Jun 13 2015 00:49:16
%S 3,28,255,2296,20667,186004,1674039,15066352,135597171,1220374540,
%T 10983370863,98850337768,889653039915,8006877359236,72061896233127,
%U 648557066098144,5837013594883299
%N Base 9 digits are, in order, the first n terms of the periodic sequence with initial period 3,1.
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (9,1,-9).
%F G.f.: x*(3+x) / ( (x-1)*(9*x-1)*(1+x) ). - _R. J. Mathar_, Apr 27 2015
%F a(n) = 7*9^n/20 -1/4 +(-1)^(n+1)/10. - _R. J. Mathar_, Apr 27 2015
%t With[{c=PadLeft[{},20,{3,1}]},Table[FromDigits[Take[c,n],9],{n,20}]] (* _Harvey P. Dale_, Oct 15 2011 *)
%K nonn,base,easy
%O 1,1
%A _Clark Kimberling_