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A086948 a(n) = k where R(k+8) = 2.

%I A086948 #21 May 02 2025 11:09:27
%S A086948 12,192,1992,19992,199992,1999992,19999992,199999992,1999999992,
%T A086948 19999999992,199999999992,1999999999992,19999999999992,
%U A086948 199999999999992,1999999999999992,19999999999999992,199999999999999992,1999999999999999992,19999999999999999992,199999999999999999992
%N A086948 a(n) = k where R(k+8) = 2.
%H A086948 Vincenzo Librandi, <a href="/A086948/b086948.txt">Table of n, a(n) for n = 1..300</a>
%H A086948 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10).
%F A086948 a(n) = 2*(10^n - 4).
%F A086948 R(a(n)) = A086947(n).
%F A086948 From _Chai Wah Wu_, Aug 01 2020: (Start)
%F A086948 a(n) = 11*a(n-1) - 10*a(n-2) for n > 2.
%F A086948 G.f.: x*(60*x + 12)/((x - 1)*(10*x - 1)). (End)
%F A086948 From _Elmo R. Oliveira_, May 01 2025: (Start)
%F A086948 E.g.f.: 2*(3 - 4*exp(x) + exp(10*x)).
%F A086948 a(n) = 12*A246057(n-1) = 6*A323639(n). (End)
%t A086948 Table[10*FromDigits[PadRight[{1},n,9]]+2,{n,20}] (* _Harvey P. Dale_, Dec 15 2017 *)
%o A086948 (Magma) [2*(10^n-4): n in [1..25] ]; // _Vincenzo Librandi_, Aug 22 2011
%Y A086948 Cf. A004086, A085331, A086947, A246057, A323639.
%K A086948 nonn,base,easy
%O A086948 1,1
%A A086948 _Ray Chandler_, Jul 24 2003