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 A121199 #17 Sep 08 2022 08:45:27
%S A121199 2,24,98,504,3074,19992,133346,901752,6155522,42306840,292240994,
%T A121199 2026155000,14085427970,98109713688,684326588642,4778079088248,
%U A121199 33385518460418,233393453440536,1632228295176290,11417968671701496
%N A121199 12n+7^n+5^n.
%H A121199 Vincenzo Librandi, <a href="/A121199/b121199.txt">Table of n, a(n) for n = 0..1000</a>
%H A121199 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (14,-60,82,-35).
%F A121199 G.f.: 2*(1-2*x-59*x^2+204*x^3)/((1-x)^2*(1-7*x)*(1-5*x)). - _Vincenzo Librandi_, Feb 23 2013
%t A121199 CoefficientList[Series[2 (1 - 2 x - 59 x^2 + 204 x^3)/((1-x)^2 (1-7 x) (1-5 x)), {x, 0, 20}], x] (* _Vincenzo Librandi_, Feb 23 2013 *)
%t A121199 Table[12 n + 7^n + 5^n, {n, 0, 20}] (* _Bruno Berselli_, Feb 27 2013 *)
%t A121199 LinearRecurrence[{14,-60,82,-35},{2,24,98,504},20] (* _Harvey P. Dale_, Aug 15 2013 *)
%o A121199 (PARI) for(n=0, 20, print1(12*n+7^n+5^n", ")); \\ _Bruno Berselli_, Feb 27 2013
%o A121199 (Magma) [12*n+7^n+5^n: n in [0..20]]; // _Bruno Berselli_, Feb 27 2013
%Y A121199 Cf. A074616.
%K A121199 nonn,easy
%O A121199 0,1
%A A121199 _Mohammad K. Azarian_, Aug 19 2006
%E A121199 Edited by _Ray Chandler_, Sep 06 2006