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 A048491 #28 Feb 05 2022 16:21:28
%S A048491 1,10,28,64,136,280,568,1144,2296,4600,9208,18424,36856,73720,147448,
%T A048491 294904,589816,1179640,2359288,4718584,9437176,18874360,37748728,
%U A048491 75497464,150994936,301989880,603979768,1207959544,2415919096
%N A048491 a(n) = T(8,n), array T given by A048483.
%C A048491 n-th difference of a(n), a(n-1), ..., a(0) is (9, 9, 9, ...).
%H A048491 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (3, -2).
%F A048491 a(n) = 9 * 2^n - 8. - _Ralf Stephan_
%F A048491 Equals binomial transform of [1, 9, 9, 9, ...]. - _Gary W. Adamson_, Apr 29 2008
%F A048491 a(n) = 2*a(n-1) + 8, with a(0)=1. - _Vincenzo Librandi_, Aug 06 2010
%F A048491 a(n) = 2*A053209(n), n>0. - _Philippe Deléham_, Apr 15 2013
%F A048491 a(n) = 3*a(n-1) - 2*a(n-2) with a(0)=1, a(1)=10. - _Philippe Deléham_, Apr 15 2013
%F A048491 G.f.: (1+7*x)/((1-x)*(1-2*x)). - _Philippe Deléham_, Apr 15 2013
%t A048491 a=1; lst={a}; k=9; Do[a+=k; AppendTo[lst, a]; k+=k, {n, 0, 5!}]; lst (* _Vladimir Joseph Stephan Orlovsky_, Dec 16 2008 *)
%t A048491 9*2^Range[0,30]-8 (* _Harvey P. Dale_, May 14 2021 *)
%K A048491 nonn,easy
%O A048491 0,2
%A A048491 _Clark Kimberling_