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%I #12 Nov 22 2019 17:44:55
%S 12,372,3972,39972,399972,3999972,39999972,399999972,3999999972,
%T 39999999972,399999999972,3999999999972,39999999999972,
%U 399999999999972,3999999999999972,39999999999999972,399999999999999972
%N 4*(10^n-7).
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10).
%F G.f. 12*x*(1+20*x) / ( (10*x-1)*(x-1) ). - R. J. Mathar, Aug 24 2011
%F a(n) = 12 *A033175(n-1). - R. J. Mathar, Aug 24 2011
%t 4(10^Range[20]-7) (* or *) LinearRecurrence[{11,-10},{12,372},20] (* _Harvey P. Dale_, Nov 22 2019 *)
%K nonn,easy
%O 1,1
%A _Vincenzo Librandi_