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 A035302 #16 Jul 08 2025 21:32:19
%S A035302 0,1,-2,-8,-4,16,16,-48,-96,64,320,0,-1024,-768,2560,4096,-5120,
%T A035302 -16384,4096,53248,24576,-147456,-180224,327680,786432,-458752,
%U A035302 -2752512,-524288,8126464,7340032,-19922944,-36700160,35651584
%N A035302 a(n+1)=2a(n)-4a(n-1)+4a(n-2).
%H A035302 Reinhard Zumkeller, <a href="/A035302/b035302.txt">Table of n, a(n) for n = 0..1000</a>
%H A035302 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (2, -4, 4).
%F A035302 G.f.: (x-4*x^2)/(1-2*x+4*x^2-4*x^3).
%t A035302 LinearRecurrence[{2,-4,4},{0,1,-2},40] (* _Harvey P. Dale_, Dec 01 2024 *)
%o A035302 (Haskell)
%o A035302 a035302 n = a035302_list !! (n-1)
%o A035302 a035302_list = 0 : 1 : (-2) :
%o A035302 zipWith (+) (drop 2 $ map (* 2) a035302_list)
%o A035302 (map (* 4) $ zipWith (-) a035302_list $ tail a035302_list)
%o A035302 -- _Reinhard Zumkeller_, Mar 18 2012
%Y A035302 Cf. A007420.
%K A035302 sign
%O A035302 0,3
%A A035302 _N. J. A. Sloane_