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 A155634 #16 Jun 02 2021 11:37:19
%S A155634 1,11,73,467,3025,19931,133273,901667,6155425,42306731,292240873,
%T A155634 2026154867,14085427825,98109713531,684326588473,4778079088067,
%U A155634 33385518460225,233393453440331,1632228295176073,11417968671701267
%N A155634 7^n + 5^n - 1.
%H A155634 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (13,-47,35).
%F A155634 G.f.: 1/(1-7*x)+1/(1-5*x)-1/(1-x). E.g.f.: e^(7*x)+e^(5*x)-e^x.
%F A155634 a(n)=12*a(n-1)-35*a(n-2)-24 with a(0)=1, a(1)=11 [From _Vincenzo Librandi_, Jul 21 2010]
%t A155634 Table[7^n+5^n-1,{n,0,30}] (* or *) LinearRecurrence[{13,-47,35},{1,11,73},30] (* _Harvey P. Dale_, Jun 02 2021 *)
%o A155634 (PARI) a(n)=7^n+5^n-1 \\ _Charles R Greathouse IV_, Dec 22 2011
%K A155634 nonn,easy
%O A155634 0,2
%A A155634 _Mohammad K. Azarian_, Jan 30 2009