%I #11 Sep 08 2022 08:45:50
%S 5,15,115,1115,11115,111115,1111115,11111115,111111115,1111111115,
%T 11111111115,111111111115,1111111111115,11111111111115,
%U 111111111111115,1111111111111115,11111111111111115,111111111111111115
%N (10^n+35)/9 for n>0.
%H Vincenzo Librandi, <a href="/A173736/b173736.txt">Table of n, a(n) for n = 1..100</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10).
%F a(n) = a(n-1)+10^(n-1) = 10*a(n-1)-35 with n>0, a(0)=4.
%F G.f.: x*(5-40*x)/((1-x)*(1-10*x)). - _Vincenzo Librandi_, Jul 05 2012
%F a(n) = 11*a(n-1) -10*a(n-2). - _Vincenzo Librandi_, Jul 05 2012
%t CoefficientList[Series[(5-40*x)/((1-x)*(1-10*x)),{x,0,30}],x] (* _Vincenzo Librandi_, Jul 05 2012 *)
%o (Magma) [(10^n+35)/9: n in [1..20]]; // _Vincenzo Librandi_, Jul 05 2012
%K nonn,easy
%O 1,1
%A _Vincenzo Librandi_, Feb 23 2010