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 A010679 #22 Jul 08 2025 01:44:22
%S A010679 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 A010679 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 A010679 0,8,0,8,0,8,0,8,0,8,0,8,0
%N A010679 Period 2: repeat (0,8).
%H A010679 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (0,1).
%F A010679 a(n) = 4*(1-(-1)^n) = 8*(n mod 2). - _Paolo P. Lava_, Oct 20 2006
%F A010679 G.f.: 8*x/((1-x)*(1+x)). - _R. J. Mathar_, Nov 21 2011
%F A010679 a(n) = 3^(1-(-1)^n) - 1. - _Bruno Berselli_, Dec 29 2015
%t A010679 PadRight[{},120,{0,8}] (* _Harvey P. Dale_, Dec 21 2015 *)
%o A010679 (Magma) &cat [[0,8]^^40]; // _Bruno Berselli_, Dec 29 2015
%o A010679 (PARI) a(n)=n%2*8 \\ _Charles R Greathouse IV_, Jul 26 2016
%Y A010679 Cf. A010700: 3^(1-(-1)^n) + 1.
%K A010679 nonn,easy
%O A010679 0,2
%A A010679 _N. J. A. Sloane_