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%I #20 Sep 08 2022 08:44:37
%S 0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,
%T 0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,0,8,
%U 0,8,0,8,0,8,0,8,0,8,0,8,0
%N Period 2: repeat (0,8).
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (0,1).
%F a(n) = 4*(1-(-1)^n) = 8*(n mod 2). - _Paolo P. Lava_, Oct 20 2006
%F G.f.: 8*x/((1-x)*(1+x)). - _R. J. Mathar_, Nov 21 2011
%F a(n) = 3^(1-(-1)^n) - 1. - _Bruno Berselli_, Dec 29 2015
%t PadRight[{},120,{0,8}] (* _Harvey P. Dale_, Dec 21 2015 *)
%o (Magma) &cat [[0,8]^^40]; // _Bruno Berselli_, Dec 29 2015
%o (PARI) a(n)=n%2*8 \\ _Charles R Greathouse IV_, Jul 26 2016
%Y Cf. A010700: 3^(1-(-1)^n) + 1.
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_.
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