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 A191468 #23 Apr 01 2025 03:30:28
%S A191468 0,3,39,387,3471,29643,246519,2019027,16386591,132264603,1063976199,
%T A191468 8541106467,68475336111,548535110763,4391942995479,35153854510707,
%U A191468 281322388820031,2251036874232123,18010583812216359,144096114589527747,1152826137175206351,9222895199696572683
%N A191468 a(n) = 8^n - 5^n.
%H A191468 Vincenzo Librandi, <a href="/A191468/b191468.txt">Table of n, a(n) for n = 0..300</a>
%H A191468 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (13,-40).
%F A191468 a(n) = 13*a(n-1) - 40*a(n-2).
%F A191468 From _Vincenzo Librandi_, Oct 05 2014: (Start)
%F A191468 G.f.: 3*x/((1-5*x)*(1-8*x)).
%F A191468 a(n+1) = 3*A016162(n). (End)
%F A191468 E.g.f.: 2*exp(13*x/2)*sinh(3*x/2). - _Elmo R. Oliveira_, Mar 31 2025
%t A191468 Table[8^n-5^n,{n,0,20}] (* or *) LinearRecurrence[{13,-40},{0,3},30] (* _Harvey P. Dale_, Dec 04 2012 *)
%t A191468 CoefficientList[Series[3 x/((1 - 5 x) (1 - 8 x)), {x, 0, 30}], x] (* _Vincenzo Librandi_, Oct 05 2014 *)
%o A191468 (Magma) [8^n - 5^n: n in [0..20]];
%o A191468 (PARI) a(n)=8^n-5^n \\ _Charles R Greathouse IV_, Jun 08 2011
%Y A191468 Cf. A016162, A016177.
%K A191468 nonn,easy
%O A191468 0,2
%A A191468 _Vincenzo Librandi_, Jun 03 2011