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 A155624 #15 Nov 02 2021 11:17:47
%S A155624 1,9,113,1305,14561,160809,1770833,19484985,214352321,2357928009,
%T A155624 25937365553,285311493465,3138427845281,34522710549609,
%U A155624 379749828800273,4177248155066745,45949729820525441,505447028370153609
%N A155624 11^n-3^n+1.
%H A155624 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (15,-47,33).
%F A155624 G.f.: 1/(1-11*x)-1/(1-3*x)+1/(1-x). E.g.f.: e^(11*x)-e^(3*x)+e^x.
%F A155624 a(n)=14*a(n-1)-33*a(n-2)+20 with a(0)=1, a(1)=9 - _Vincenzo Librandi_, Jul 21 2010
%t A155624 LinearRecurrence[{15,-47,33},{1,9,113},20] (* _Harvey P. Dale_, Nov 02 2021 *)
%o A155624 (PARI) a(n)=11^n-3^n+1 \\ _Charles R Greathouse IV_, Jun 11 2015
%Y A155624 Cf. A155588, A155589, A155590, A155592, A155593, A155594, A155595, A155596, A155597, A155598, A155599, A155600, A155601, A155622, A155623.
%K A155624 nonn,easy
%O A155624 0,2
%A A155624 _Mohammad K. Azarian_, Jan 29 2009