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 A372148 #20 May 25 2024 15:32:02
%S A372148 1,14,86,374,1382,4694,15206,47894,148262,453974,1380326,4177814,
%T A372148 12607142,37968854,114201446,343194134,1030762022,3094645334,
%U A372148 9288654566,27875400854,83645076902,250972979414,752994435686,2259134301974
%N A372148 a(n) = A371764(n, 2).
%H A372148 Paolo Xausa, <a href="/A372148/b372148.txt">Table of n, a(n) for n = 1..1000</a>
%H A372148 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (6,-11,6).
%F A372148 a(n) = 2*(4*3^n - 9*2^n + 7) - [n = 1]. - _Hugo Pfoertner_, Apr 20 2024
%F A372148 G.f.: x*(1 + 8*x + 13*x^2 + 6*x^3)/((1 - x)*(1 - 2*x)*(1 - 3*x)). - _Stefano Spezia_, Apr 21 2024
%p A372148 a := n -> 2*(4*3^n - 9*2^n + 7) - `if`(n=1, 1, 0);
%p A372148 seq(a(n), n = 1..24); # _Peter Luschny_, Apr 20 2024
%t A372148 A372148[n_] := 2*(4*3^n - 9*2^n + 7) - Boole[n == 1]; Array[A372148,50] (* or *)
%t A372148 LinearRecurrence[{6, -11, 6}, {1, 14, 86, 374}, 50] (* _Paolo Xausa_, May 25 2024 *)
%Y A372148 Cf. A371764.
%K A372148 nonn,easy
%O A372148 1,2
%A A372148 _Detlef Meya_, Apr 20 2024