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 A139746 #18 Apr 01 2025 07:12:03
%S A139746 0,3,57,819,10545,128283,1509417,17390019,197581665,2223729963,
%T A139746 24863682777,276721736019,3069708899985,33972956330043,
%U A139746 375351787072137,4142063797326819,45668254886861505,503195228685608523,5541902914982749497,61014975260338690419,671597073427953162225
%N A139746 a(n) = 11^n - 8^n.
%H A139746 Vincenzo Librandi, <a href="/A139746/b139746.txt">Table of n, a(n) for n = 0..300</a>
%H A139746 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (19,-88).
%F A139746 a(n) = 19*a(n-1) - 88*a(n-2). - _Vincenzo Librandi_, Jun 02 2011
%F A139746 From _Elmo R. Oliveira_, Apr 01 2025: (Start)
%F A139746 G.f.: 3*x/((1-8*x)*(1-11*x)).
%F A139746 E.g.f.: 2*exp(19*x/2)*sinh(3*x/2).
%F A139746 a(n) = 3*A016187(n-1) for n >= 1. (End)
%t A139746 Table[11^n-8^n,{n,0,30}] (* or *) LinearRecurrence[{19,-88},{0,3},30] (* _Harvey P. Dale_, Apr 13 2019 *)
%o A139746 (Magma) [11^n-8^n: n in [0..30]]; // _Vincenzo Librandi_, Jun 02 2011
%Y A139746 Cf. A016187.
%K A139746 nonn,easy
%O A139746 0,2
%A A139746 _N. J. A. Sloane_, May 20 2008