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 A059505 #15 Sep 10 2017 20:04:22
%S A059505 2,5,14,40,114,323,910,2551,7120,19796,54852,151525,417434,1147145,
%T A059505 3145394,8606848,23507190,64093031,174474790,474261691,1287398452,
%U A059505 3490267820,9451319304,25565098825,69080289074
%N A059505 Transform of A059502 applied to sequence 2,3,4,...
%C A059505 The second row of the array A059503.
%H A059505 G. C. Greubel, <a href="/A059505/b059505.txt">Table of n, a(n) for n = 1..1000</a>
%H A059505 <a href="/index/Bo#boustrophedon">Index entries for sequences related to boustrophedon transform</a>
%H A059505 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (6,-11,6,-1).
%F A059505 G.f.: x*(2 - 7*x + 6*x^2 - x^3)/(1 - 3*x + x^2)^2.
%F A059505 From _G. C. Greubel_, Sep 10 2017: (Start)
%F A059505 a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3) - a(n-4).
%F A059505 a(n) = ((3 - n)*Fibonacci(2*n) + (5 + 3*n)*Fibonacci(2*n - 1))/5. (End)
%t A059505 LinearRecurrence[{6,-11,6,-1},{2,5,14,40}, 50] (* or *) Rest[CoefficientList[Series[x*(2 - 7*x + 6*x^2 - x^3)/(1 - 3*x + x^2)^2, {x,0,50}], x]] (* _G. C. Greubel_, Sep 10 2017 *)
%o A059505 (PARI) x='x+O('x^50); Vec(x*(2-7*x+6*x^2-x^3)/(1-3*x+x^2)^2) \\ _G. C. Greubel_, Sep 10 2017
%Y A059505 Cf. A000667, A059216, A059219, A059502.
%K A059505 easy,nonn
%O A059505 1,1
%A A059505 _Floor van Lamoen_, Jan 19 2001