This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A027937 #28 Sep 08 2022 08:44:49
%S A027937 1,7,26,79,221,596,1581,4163,10926,28635,75001,196392,514201,1346239,
%T A027937 3524546,9227431,24157781,63245948,165580101,433494395,1134903126,
%U A027937 2971215027,7778742001,20365011024,53316291121
%N A027937 a(n) = T(2*n, n+1), T given by A027935.
%H A027937 G. C. Greubel, <a href="/A027937/b027937.txt">Table of n, a(n) for n = 1..1000</a>
%H A027937 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (5,-8,5,-1).
%F A027937 a(n) = Fibonacci(2*n+3) - 2*n - 2.
%F A027937 From _R. J. Mathar_, Feb 06 2010: (Start)
%F A027937 a(n) = 5*a(n-1) - 8*a(n-2) + 5*a(n-3) - a(n-4);
%F A027937 G.f.: x*(1 + 2*x - x^2)/((1-3*x+x^2)*(1-x)^2). (End)
%p A027937 with(combinat); seq(fibonacci(2*n+3) -2*(n+1), n=1..30); # _G. C. Greubel_, Sep 27 2019
%t A027937 Table[Fibonacci[2*n+3]-2*(n+1), {n,30}] (* _G. C. Greubel_, Sep 27 2019 *)
%o A027937 (Magma) [Fibonacci(2*n+3) - 2*n - 2: n in [1..30]]; // _Vincenzo Librandi_, Apr 18 2011
%o A027937 (PARI) vector(30, n, fibonacci(2*n+3)-2*(n+1)) \\ _G. C. Greubel_, Sep 27 2019
%o A027937 (Sage) [fibonacci(2*n+3) -2*(n+1) for n in (1..30)] # _G. C. Greubel_, Sep 27 2019
%o A027937 (GAP) List([1..30], n-> Fibonacci(2*n+3) -2*(n+1) ); # _G. C. Greubel_, Sep 27 2019
%Y A027937 Cf. A000045, A027935.
%K A027937 nonn,easy
%O A027937 1,2
%A A027937 _Clark Kimberling_