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a(n) = k where R(k+4) = 2.
2

%I #16 Sep 08 2022 08:45:11

%S 16,196,1996,19996,199996,1999996,19999996,199999996,1999999996,

%T 19999999996,199999999996,1999999999996,19999999999996,

%U 199999999999996,1999999999999996,19999999999999996,199999999999999996,1999999999999999996,19999999999999999996

%N a(n) = k where R(k+4) = 2.

%C R(a(n)) = A086945(n).

%H Vincenzo Librandi, <a href="/A086940/b086940.txt">Table of n, a(n) for n = 1..300</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11, -10).

%F a(n) = 2*(10^n-2).

%F a(n) = 11*a(n-1) - 10*a(n-2); a(1)=16, a(2)=196. - _Harvey P. Dale_, Aug 11 2012

%t Table[FromDigits[Join[PadRight[{1},n,9],{6}]],{n,20}] (* or *) 2 (10^Range[20] - 2) (* or *) LinearRecurrence[{11,-10},{16,196},20] (* _Harvey P. Dale_, Aug 11 2012 *)

%o (Magma) [2*(10^n-2): n in [1..20] ]; // _Vincenzo Librandi_, Aug 22 2011

%K nonn,easy

%O 1,1

%A _Ray Chandler_, Jul 24 2003