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 A122611 #15 Sep 18 2017 10:27:50
%S A122611 1,7,34,139,516,1802,6039,19657,62634,196404,608361,1866462,5683236,
%T A122611 17200871,51807242,155421557,464755958,1386055506,4124569714,
%U A122611 12251283960,36334754000,107624090145,318444202635,941387240040
%N A122611 G.f.: 1/(1 - 7 x + 15 x^2 - 6 x^3 - 11 x^4 + 6 x^5 + x^6).
%H A122611 Peter Steinbach, <a href="http://www.jstor.org/stable/2691048">Golden fields: a case for the heptagon</a>, Math. Mag. Vol. 70, No. 1, Feb. 1997, 22-31.
%H A122611 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (7,-15,6,11,-6,-1).
%t A122611 b = {1, -7, 15, -6, -11, 6, 1}; p[x_] := Sum[x^(n - 1)*b[[8 - n]], {n, 1, 7}] q[x_] := ExpandAll[x^6*p[1/x]] Table[ SeriesCoefficient[ Series[x/q[x], {x, 0, 30}], n], {n, 0, 30}]
%Y A122611 Cf. A066170.
%K A122611 nonn,easy
%O A122611 1,2
%A A122611 _Roger L. Bagula_ and _Gary W. Adamson_, Sep 20 2006
%E A122611 Edited by _N. J. A. Sloane_, Sep 21 2006