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 A110689 #11 Sep 06 2017 21:17:21
%S A110689 1,3,-18,63,-207,696,-2415,8565,-30714,110583,-398439,1435152,
%T A110689 -5167083,18598065,-66931314,240862563,-866772819,3119198160,
%U A110689 -11224913079,40394716341,-145367356794,523129840335,-1882574375679,6774773362320,-24380205972915
%N A110689 Expansion of (2*x+1)*(4*x^2+8*x+1)/((3*x^2+3*x+1)*(2*x^3+2*x^2+4*x+1)).
%H A110689 G. C. Greubel, <a href="/A110689/b110689.txt">Table of n, a(n) for n = 0..1000</a>
%H A110689 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (-7,-17,-20,-12,-6).
%p A110689 seriestolist(series((2*x+1)*(4*x^2+8*x+1)/((3*x^2+3*x+1)*(2*x^3+2*x^2+4*x+1)), x=0,25)); -or- Floretion Algebra Multiplication Program, FAMP Code: tessum(infty)-4basekforsumseq[ + 'i - .25'j + .25'k - .25j' + .25k' - .5'ii' - .25'ij' - .25'ik' - .25'ji' - .25'ki' - .5e], Sumtype is set to: default; Fortype is set to: 1A.
%t A110689 CoefficientList[Series[(2*x + 1)*(4*x^2 + 8*x + 1)/((3*x^2 + 3*x + 1)*(2*x^3 + 2*x^2 + 4*x + 1)), {x, 0, 50}], x] (* _G. C. Greubel_, Sep 06 2017 *)
%o A110689 (PARI) Vec((2*x+1)*(4*x^2+8*x+1)/((3*x^2+3*x+1)*(2*x^3+2*x^2+4*x+1))+O(x^99)) \\ _Charles R Greathouse IV_, Sep 26 2012
%Y A110689 Cf. A110687, A110688, A110679.
%K A110689 sign,easy
%O A110689 0,2
%A A110689 _Creighton Dement_, Aug 02 2005