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 A259109 #16 Jul 18 2020 17:53:26
%S A259109 0,2,130,1588,9780,41030,134342,369640,893928,1956810,3956810,7499932,
%T A259109 13471900,23125518,38184590,60965840,94520272,142795410,210819858,
%U A259109 304911620,432911620,604443862,831203670,1127275448,1509481400,1997762650,2615594202,3390435180
%N A259109 2*A000540.
%H A259109 Colin Barker, <a href="/A259109/b259109.txt">Table of n, a(n) for n = 0..1000</a>
%H A259109 J. L. Bailey, Jr., <a href="http://dx.doi.org/10.1214/aoms/1177732978">A table to facilitate the fitting of certain logistic curves</a>, Annals Math. Stat., 2 (1931), 355-359.
%H A259109 J. L. Bailey, <a href="/A002309/a002309.pdf">A table to facilitate the fitting of certain logistic curves</a>, Annals Math. Stat., 2 (1931), 355-359. [Annotated scanned copy]
%H A259109 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (8,-28,56,-70,56,-28,8,-1).
%F A259109 a(n) = n/21-n^3/3+n^5+n^6+(2*n^7)/7. - _Colin Barker_, Jun 28 2015
%F A259109 G.f.: 2*x*(x+1)*(x^4+56*x^3+246*x^2+56*x+1) / (x-1)^8. - _Colin Barker_, Jun 28 2015
%t A259109 LinearRecurrence[{8,-28,56,-70,56,-28,8,-1},{0,2,130,1588,9780,41030,134342,369640},30] (* _Harvey P. Dale_, Jul 18 2020 *)
%o A259109 (PARI) concat(0, Vec(2*x*(x+1)*(x^4+56*x^3+246*x^2+56*x+1)/(x-1)^8 + O(x^100))) \\ _Colin Barker_, Jun 28 2015
%Y A259109 Cf. A000540.
%K A259109 nonn,easy
%O A259109 0,2
%A A259109 _N. J. A. Sloane_, Jun 24 2015