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 A164044 #11 Sep 09 2017 03:22:18
%S A164044 1,3,10,37,144,571,2278,9105,36412,145639,582546,2330173,9320680,
%T A164044 37282707,149130814,596523241,2386092948,9544371775,38177487082,
%U A164044 152709948309,610839793216,2443359172843,9773436691350,39093746765377
%N A164044 a(n+1) = 4*a(n) - n.
%H A164044 G. C. Greubel, <a href="/A164044/b164044.txt">Table of n, a(n) for n = 0..1000</a>
%H A164044 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (6, -9, 4).
%F A164044 a(0)=1; a(n+1) = 4*a(n) - n.
%F A164044 a(n) = (5*4^n + 3*n + 4)/9.
%F A164044 From _R. J. Mathar_, Aug 09 2009: (Start)
%F A164044 a(n) = 6*a(n-1) - 9*a(n-2) + 4*a(n-3).
%F A164044 G.f.: (1-3*x+x^2)/((1-4*x)*(1-x)^2). (End)
%F A164044 E.g.f.: (1/9)*(5*exp(4*x) + (3*x + 4)*exp(x)). - _G. C. Greubel_, Sep 08 2017
%t A164044 Table[(5*4^n + 3*n + 4)/9, {n,0,50}] (* _G. C. Greubel_, Sep 08 2017 *)
%o A164044 (PARI) x='x+O('x^50); Vec((1-3*x+x^2)/((1-4*x)*(1-x)^2)) \\ _G. C. Greubel_, Sep 08 2017
%K A164044 nonn
%O A164044 0,2
%A A164044 _Rolf Pleisch_, Aug 08 2009