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 A167477 #13 Jun 14 2016 11:49:50
%S A167477 1,3,12,44,149,479,1487,4503,13386,39226,113641,326173,928957,2628459,
%T A167477 7395624,20708264,57739517,160391483,444068171,1225831551,3374848806,
%U A167477 9268963318,25401364177,69472849849,189661024249,516904018899
%N A167477 Expansion of (1-3x+5x^2-x^3)/(1-3x+x^2)^2.
%C A167477 Hankel transform of A033297 (when this starts 1,1,4,...).
%H A167477 G. C. Greubel, <a href="/A167477/b167477.txt">Table of n, a(n) for n = 0..1000</a>
%H A167477 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (6,-11,6,-1).
%F A167477 a(n) = 4*A001871(n-1) - A001871(n) + A001519(n+2). - _R. J. Mathar_, Jun 28 2011
%t A167477 LinearRecurrence[{6, -11, 6, -1}, {1, 3, 12, 44}, 100] (* _G. C. Greubel_, Jun 13 2016 *)
%K A167477 easy,nonn
%O A167477 0,2
%A A167477 _Paul Barry_, Nov 04 2009