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 A051667 #29 Oct 27 2023 22:00:44
%S A051667 0,2,10,30,74,166,354,734,1498,3030,6098,12238,24522,49094,98242,
%T A051667 196542,393146,786358,1572786,3145646,6291370,12582822,25165730,
%U A051667 50331550,100663194,201326486,402653074,805306254,1610612618,3221225350,6442450818,12884901758,25769803642
%N A051667 a(n) = 6*2^n - 4*n - 6.
%H A051667 Vincenzo Librandi, <a href="/A051667/b051667.txt">Table of n, a(n) for n = 0..1000</a>
%H A051667 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (4,-5,2).
%F A051667 From _Colin Barker_, Jun 24 2012: (Start)
%F A051667 a(n) = 4*a(n-1) - 5*a(n-2) + 2*a(n-3).
%F A051667 G.f.: 2*x*(1 + x)/((1 - x)^2*(1 - 2*x)). (End)
%F A051667 E.g.f.: 2*exp(x)*(3*exp(x) - 2*x - 3). - _Stefano Spezia_, May 15 2023
%t A051667 CoefficientList[Series[2 x (1 + x)/((1 - x)^2 (1 - 2 x)), {x, 0, 40}], x] (* _Vincenzo Librandi_, Jul 05 2012 *)
%o A051667 (Magma) I:=[0, 2, 10]; [n le 3 select I[n] else 4*Self(n-1)-5*Self(n-2)+2*Self(n-3): n in [1..30]]; // _Vincenzo Librandi_, Jul 04 2012
%Y A051667 Row sums of A051666.
%Y A051667 Equals 2 * A050488.
%Y A051667 Cf. A000290.
%K A051667 nonn,easy
%O A051667 0,2
%A A051667 _Asher Auel_