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 A165751 #18 Oct 08 2024 06:24:23
%S A165751 1,-2,-8,-20,-44,-92,-188,-380,-764,-1532,-3068,-6140,-12284,-24572,
%T A165751 -49148,-98300,-196604,-393212,-786428,-1572860,-3145724,-6291452,
%U A165751 -12582908,-25165820,-50331644,-100663292,-201326588,-402653180,-805306364,-1610612732,-3221225468
%N A165751 a(n) = 4 - 3*2^n.
%H A165751 G. C. Greubel, <a href="/A165751/b165751.txt">Table of n, a(n) for n = 0..500</a>
%H A165751 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (3,-2).
%F A165751 a(n) = 2*a(n-1) - 4, a(0)=1.
%F A165751 a(n) = Sum_{0<=k<=n} A112555(n,k)*(-3)^(n-k).
%F A165751 G.f.: (1-5x)/(1-3x+2x^2).
%F A165751 From _G. C. Greubel_, Apr 07 2016: (Start)
%F A165751 a(n) = 3*a(n-1) - 2*a(n-2).
%F A165751 E.g.f.: 4*exp(x) - 3*exp(2*x). (End)
%F A165751 a(n) = -A131128(n) for n>=1. - _R. J. Mathar_, Feb 27 2019
%t A165751 Table[4 - 3*2^n, {n, 0, 50}] (* or *) LinearRecurrence[{3,-2}, {1,-2}, 50] (* _G. C. Greubel_, Apr 07 2016 *)
%o A165751 (PARI) my(x='x+O('x^99)); Vec((1-5*x)/(1-3*x+2*x^2)) \\ _Altug Alkan_, Apr 07 2016
%Y A165751 Cf. A131128.
%K A165751 easy,sign
%O A165751 0,2
%A A165751 _Philippe Deléham_, Sep 26 2009