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 A103750 #10 Jul 31 2015 17:26:52
%S A103750 1,1,1,2,3,4,4,5,7,11,14,17,20,28,39,53,65,82,107,148,196,253,319,419,
%T A103750 558,745,964,1244,1615,2141,2825,3698,4787,6244,8196,10805,14135,
%U A103750 18427,24014,31489,41332,54172,70711,92357,120849,158482,207547,271412,354628,464045
%N A103750 Expansion of (1+2*x^3)/(1-x+x^3-2*x^4).
%C A103750 Set n=4, p=2, q=-1 and r=-1 in the characteristic polynomial x^n-p*x^(n-1)+q*x+r=0.
%H A103750 Richard Kenyon, <a href="http://arXiv.org/abs/math.MG/9505210">The Construction of Self-Similar Tilings</a>, arXiv:math.MG/9505210
%H A103750 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (1, 0, -1, 2).
%F A103750 a(n) = a(n-1) -a(n-3) +2*a(n-4).
%t A103750 CoefficientList[Series[(1+2x^3)/(1-x+x^3-2x^4),{x,0,50}],x] (* or *) LinearRecurrence[{1,0,-1,2},{1,1,1,2},50] (* _Harvey P. Dale_, Mar 30 2012 *)
%Y A103750 Cf. A099206.
%K A103750 nonn,easy
%O A103750 0,4
%A A103750 _Roger L. Bagula_, Mar 28 2005
%E A103750 All values replaced consistent with the recurrence - the Assoc. Eds. of the OEIS - Jul 31 2010