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 A027978 #12 Sep 08 2022 08:44:49
%S A027978 1,11,42,145,473,1484,4529,13543,39870,115937,333781,953056,2702497,
%T A027978 7618115,21365778,59657329,165926609,459905588,1270819025,3501855007,
%U A027978 9625627686,26398369601,72248624077,197361589960,538199264833
%N A027978 a(n) = self-convolution of row n of array T given by A027960.
%H A027978 G. C. Greubel, <a href="/A027978/b027978.txt">Table of n, a(n) for n = 0..1000</a>
%H A027978 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (6,-11,6,-1).
%F A027978 From _Colin Barker_, Feb 25 2015: (Start)
%F A027978 a(n) = 5*a(n-1) - 5*a(n-2) - 5*a(n-3) + 5*a(n-4) - a(n-5).
%F A027978 G.f.: (1 +5*x -13*x^2 +8*x^3)/(1-3*x+x^2)^2. (End)
%F A027978 a(n) = 2*(n+1)*Lucas(2*n) + Fibonacci(2*n-4). - _G. C. Greubel_, Oct 01 2019
%p A027978 with(combinat); f:=fibonacci; seq(2*(n+1)*(f(2*n+1) + f(2*n-1)) + f(2*n-4), n=0..40); # _G. C. Greubel_, Oct 01 2019
%t A027978 Table[2*(n+1)*LucasL[2*n] + Fibonacci[2*n-4], {n, 0, 40}] (* _G. C. Greubel_, Oct 01 2019 *)
%o A027978 (PARI) vector(41, n, f=fibonacci; 2*n*(f(2*n-1) + f(2*n-3)) + f(2*n-6)) \\ _G. C. Greubel_, Oct 01 2019
%o A027978 (Magma) [2*(n+1)*Lucas(2*n) + Fibonacci(2*n-4): n in [0..40]]; // _G. C. Greubel_, Oct 01 2019
%o A027978 (Sage) [2*(n+1)*lucas_number2(2*n,1,-1) + fibonacci(2*n-4) for n in (0..40)] # _G. C. Greubel_, Oct 01 2019
%o A027978 (GAP) List([0..40], n-> 2*(n+1)*Lucas(1,-1,2*n)[2] + Fibonacci(2*n-4) ); # _G. C. Greubel_, Oct 01 2019
%Y A027978 Cf. A000032, A000045, A027960.
%K A027978 nonn
%O A027978 0,2
%A A027978 _Clark Kimberling_