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 A022131 #22 May 08 2018 09:00:24
%S A022131 4,11,15,26,41,67,108,175,283,458,741,1199,1940,3139,5079,8218,13297,
%T A022131 21515,34812,56327,91139,147466,238605,386071,624676,1010747,1635423,
%U A022131 2646170,4281593,6927763,11209356,18137119,29346475,47483594,76830069,124313663
%N A022131 Fibonacci sequence beginning 4, 11.
%H A022131 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>
%H A022131 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (1, 1).
%F A022131 G.f.: (4+7x)/(1-x-x^2). - _Philippe Deléham_, Nov 19 2008
%F A022131 a(n) = ((10 + 9*sqrt(5))/5)*((1 + sqrt(5))/2)^n + ((10 - 9*sqrt(5))/5)*((1 - sqrt(5))/2)^n starting at n=0. - _Bogart B. Strauss_, Oct 27 2013
%t A022131 a={};b=4;c=11;AppendTo[a, b];AppendTo[a, c];Do[b=b+c;AppendTo[a, b];c=b+c;AppendTo[a, c], {n, 4!}];a (* _Vladimir Joseph Stephan Orlovsky_, Sep 17 2008 *)
%t A022131 LinearRecurrence[{1,1},{4,11},40] (* _Harvey P. Dale_, May 08 2018 *)
%Y A022131 Cf. A000032.
%K A022131 nonn,easy
%O A022131 0,1
%A A022131 _N. J. A. Sloane_