%I #16 Jul 08 2025 21:32:19

%S 0,1,-2,-8,-4,16,16,-48,-96,64,320,0,-1024,-768,2560,4096,-5120,

%T -16384,4096,53248,24576,-147456,-180224,327680,786432,-458752,

%U -2752512,-524288,8126464,7340032,-19922944,-36700160,35651584

%N a(n+1)=2a(n)-4a(n-1)+4a(n-2).

%H Reinhard Zumkeller, <a href="/A035302/b035302.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (2, -4, 4).

%F G.f.: (x-4*x^2)/(1-2*x+4*x^2-4*x^3).

%t LinearRecurrence[{2,-4,4},{0,1,-2},40] (* _Harvey P. Dale_, Dec 01 2024 *)

%o (Haskell)

%o a035302 n = a035302_list !! (n-1)

%o a035302_list = 0 : 1 : (-2) :

%o zipWith (+) (drop 2 $ map (* 2) a035302_list)

%o (map (* 4) $ zipWith (-) a035302_list $ tail a035302_list)

%o -- _Reinhard Zumkeller_, Mar 18 2012

%Y Cf. A007420.

%K sign

%O 0,3

%A _N. J. A. Sloane_