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 A086444 #12 Jan 25 2020 00:42:12
%S A086444 1,3,10,37,150,653,2990,14157,68470,335533,1657470,8227277,40957190,
%T A086444 204250413,1019649550,5093448397,25452860310,127221189293,
%U A086444 635976675230,3179495693517,15896315681830,79478090576173,397379990430510
%N A086444 Sequence associated with palindromic structures.
%C A086444 Binomial transform of A007581. Second binomial transform of A007051 (with extra leading 1).
%C A086444 Hankel transform is := [1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, ...]. - _Philippe Deléham_, Dec 04 2008
%H A086444 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (10,-31,30).
%F A086444 G.f.: (1-7x+11x^2)/((1-2x)(1-3x)(1-5x));
%F A086444 a(n) = 2^n/3 + 3^n/2 + 5^n/6.
%t A086444 LinearRecurrence[{10,-31,30},{1,3,10},30] (* _Harvey P. Dale_, Sep 14 2019 *)
%K A086444 easy,nonn
%O A086444 0,2
%A A086444 _Paul Barry_, Jul 20 2003