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%I #14 Sep 08 2022 08:45:50
%S 1,71,771,7771,77771,777771,7777771,77777771,777777771,7777777771,
%T 77777777771,777777777771,7777777777771,77777777777771,
%U 777777777777771,7777777777777771,77777777777777771,777777777777777771
%N a(n) = (7*10^n-61)/9 for n>0.
%H Vincenzo Librandi, <a href="/A173806/b173806.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) = 10*a(n-1)+61 with n>0, a(0)=-6.
%F G.f.: x*(1+60*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[(1+60*x)/((1-x)*(1-10*x)),{x,0,30}],x] (* _Vincenzo Librandi_, Jul 05 2012 *)
%o (Magma)[(7*10^n-61)/9: n in [1..20]]; // _Vincenzo Librandi_, Jul 05 2012
%Y Cf. A093176.
%K nonn,easy
%O 1,2
%A _Vincenzo Librandi_, Feb 25 2010
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