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 A121201 #27 Sep 03 2024 15:03:31
%S A121201 2,10,70,462,3018,19922,133262,901654,6155410,42306714,292240854,
%T A121201 2026154846,14085427802,98109713506,684326588446,4778079088038,
%U A121201 33385518460194,233393453440298,1632228295176038,11417968671701230
%N A121201 a(n) = 7^n+5^n-2n.
%H A121201 Vincenzo Librandi, <a href="/A121201/b121201.txt">Table of n, a(n) for n = 0..1000</a>
%H A121201 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (14,-60,82,-35).
%F A121201 G.f.: 2*(1-9*x+25*x^2-41*x^3)/((1-x)^2*(1-5*x)*(1-7*x)). - _Vincenzo Librandi_, Feb 25 2013
%F A121201 a(n) = 14*a(n-1)-60*a(n-2)+82*a(n-3)-35*a(n-4). - _Vincenzo Librandi_, Feb 26 2013
%t A121201 CoefficientList[Series[2 (1 - 9 x + 25 x^2 - 41 x^3)/((1-x)^2 (1-5 x)(1-7 x)), {x, 0, 30}], x] (* _Vincenzo Librandi_, Feb 25 2013 *)
%t A121201 LinearRecurrence[{14,-60,82,-35},{2,10,70,462},30] (* _Harvey P. Dale_, Dec 21 2014 *)
%o A121201 (Magma) [7^n+5^n-2*n: n in [0..20]]; // _Vincenzo Librandi_, Feb 25 2013
%o A121201 (Magma) I:=[2,10,70,462]; [n le 4 select I[n] else 14*Self(n-1)-60*Self(n-2)+82*Self(n-3)-35*Self(n-4): n in [1..20]]; // _Vincenzo Librandi_, Feb 25 2013
%Y A121201 Cf. A074616.
%K A121201 nonn,easy
%O A121201 0,1
%A A121201 _Mohammad K. Azarian_, Aug 19 2006
%E A121201 Edited by _Ray Chandler_, Sep 06 2006