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%I #13 Sep 08 2022 08:46:00
%S 6,39,270,1887,13206,92439,647070,4529487,31706406,221944839,
%T 1553613870,10875297087,76127079606,532889557239,3730226900670,
%U 26111588304687,182781118132806,1279467826929639,8956274788507470,62693923519552287
%N (11*7^n+1)/2.
%H Vincenzo Librandi, <a href="/A199491/b199491.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (8,-7).
%F a(n) = 7*a(n-1)-3.
%F a(n) = 8*a(n-1)-7*a(n-2).
%F G.f.: 3*(2-3*x)/((1-x)*(1-7*x)).
%t (11*7^Range[0,30]+1)/2 (* or *) LinearRecurrence[{8,-7},{6,39},30] (* _Harvey P. Dale_, Jan 23 2013 *)
%o (Magma) [(11*7^n+1)/2: n in [0..30]];
%K nonn,easy
%O 0,1
%A _Vincenzo Librandi_, Nov 07 2011