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 A048498 #21 Jun 13 2015 00:49:59
%S A048498 1,2,9,33,101,277,709,1733,4101,9477,21509,48133,106501,233477,507909,
%T A048498 1097733,2359301,5046277,10747909,22806533,48234501,101711877,
%U A048498 213909509,448790533,939524101,1962934277,4093640709,8522825733
%N A048498 2^(n-1)*(5n-8)+5.
%H A048498 Nathaniel Johnston, <a href="/A048498/b048498.txt">Table of n, a(n) for n = 0..1000</a>
%H A048498 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (5,-8,4).
%F A048498 a(0)=1, a(1)=2, a(2)=9, a(n)=5*a(n-1)-8*a(n-2)+4*a(n-3). - _Harvey P. Dale_, Jun 14 2011
%F A048498 G.f.: (-1+3*x-7*x^2)/((-1+x)(-1+2*x)^2). - _Harvey P. Dale_, Jun 14 2011
%p A048498 seq(2^(n-1)*(5*n-8)+5, n=0..27); # _Nathaniel Johnston_, Jun 14 2011
%t A048498 Table[2^(n-1) (5n-8)+5,{n,0,35}] (* or *) LinearRecurrence[{5,-8,4},{1,2,9},35] (* _Harvey P. Dale_, Jun 14 2011 *)
%o A048498 (PARI) a(n)= (5*n-8)<<(n-1)+5 \\ _Charles R Greathouse IV_, Jun 14 2011
%Y A048498 a(n)=T(4, n), array T given by A048494.
%K A048498 nonn,easy
%O A048498 0,2
%A A048498 _Clark Kimberling_
%E A048498 Formula from _Ralf Stephan_, Jan 15 2004