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 A086866 #16 Oct 02 2023 11:09:57
%S A086866 0,0,5,17,50,136,352,880,2144,5120,12032,27904,64000,145408,327680,
%T A086866 733184,1630208,3604480,7929856,17367040,37879808,82313216,178257920,
%U A086866 384827392,828375040,1778384896,3808428032,8136949760,17347641344
%N A086866 Third column of A059450.
%H A086866 Harvey P. Dale, <a href="/A086866/b086866.txt">Table of n, a(n) for n = 0..1000</a>
%H A086866 C. Coker, <a href="https://doi.org/10.1016/S0012-365X(03)00037-2">Enumerating a class of lattice paths</a>, Discrete Math., 271 (2003), 13-28.
%H A086866 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (6,-12,8).
%F A086866 For n>1, a(n) = (n^2+9n-2)*2^(n-4). - _Ralf Stephan_, May 10 2004
%t A086866 LinearRecurrence[{6,-12,8},{0,0,5,17,50},30] (* _Harvey P. Dale_, Jun 13 2016 *)
%K A086866 nonn,easy
%O A086866 0,3
%A A086866 _N. J. A. Sloane_, Sep 16 2003
%E A086866 More terms from _Ray Chandler_, Sep 17 2003