%I #18 Sep 08 2022 08:45:49
%S 5,16,16,27,27,38,38,49,49,60,60,71,71,82,82,93,93,104,104,115,115,
%T 126,126,137,137,148,148,159,159,170,170,181,181,192,192,203,203,214,
%U 214,225,225,236,236,247,247,258,258,269,269,280,280,291,291,302,302,313
%N a(n) = 5 + 11*floor(n/2).
%H Vincenzo Librandi, <a href="/A168463/b168463.txt">Table of n, a(n) for n = 1..1000</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,-1).
%F a(n) = 11*n - a(n-1) - 1, with n>1, a(1)=5.
%F G.f.: x*(5 + 11*x - 5*x^2)/((1+x)*(x-1)^2). - _Vincenzo Librandi_, Sep 19 2013
%F a(n) = a(n-1) +a(n-2) -a(n-3). - _Vincenzo Librandi_, Sep 19 2013
%F From _G. C. Greubel_, Jul 23 2016: (Start)
%F a(n) = (22*n + 11*(-1)^n + 9)/4.
%F E.g.f.: (1/4)*(11 - 20*exp(x) + (22*x + 9)*exp(2*x))*exp(-x). (End)
%t Table[5 + 11 Floor[n/2], {n, 70}] (* or *) CoefficientList[Series[(5 + 11 x - 5 x^2)/((1 + x) (x - 1)^2), {x, 0, 70}], x] (* _Vincenzo Librandi_, Sep 19 2013 *)
%t LinearRecurrence[{1,1,-1},{5,16,16},80] (* _Harvey P. Dale_, Aug 28 2019 *)
%o (Magma) [5+11*Floor(n/2): n in [1..70]]; // _Vincenzo Librandi_, Sep 19 2013
%Y Cf. A017449.
%K nonn,easy
%O 1,1
%A _Vincenzo Librandi_, Nov 26 2009
%E New definition by _Vincenzo Librandi_, Sep 19 2013