%I #57 Aug 17 2024 23:25:49
%S 3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,
%T 3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,3,6,
%U 3,6,3,6,3,6,3,6,3,6,3,6,3
%N Period 2: repeat (3,6).
%C Continued fraction expansion of A176105. - _R. J. Mathar_, Mar 08 2012
%C Digital roots of A007283. - _Bruno Berselli_, Nov 22 2018
%C Decimal expansion of 4/11. - _Franklin T. Adams-Watters_, Nov 28 2018
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (0,1).
%F G.f. 3*(1 + 2*x)/((1 - x)*(1 + x)). - _R. J. Mathar_, Nov 21 2011
%F From _Reinhard Zumkeller_, Jul 03 2012: (Start)
%F a(n) = 3*A000034(n).
%F a(n) = A213999(n,2). (End)
%F a(n + 1) = 9 - a(n). - _David A. Corneth_, Nov 29 2018
%F a(n) = 2 + 2^(1 - (-1)^n). - _Vincenzo Librandi_, Feb 28 2020
%F a(n) = 3*(3-(-1)^n)/2. - _Aaron J Grech_, Aug 02 2024
%p seq(op([3,6]),n=1..60); # _Muniru A Asiru_, Nov 29 2018
%t PadRight[{},120,{3,6}] (* _Harvey P. Dale_, Dec 12 2012 *)
%o (PARI) a(n)=3+n%2*3 \\ _Charles R Greathouse IV_, Dec 21 2011
%o (Haskell)
%o a010704 n = (* 3) . a000034
%o a010704_list = cycle [3,6] -- _Reinhard Zumkeller_, Jul 03 2012
%o (GAP) Flat(List([1..60], n->[3,6])); # _Muniru A Asiru_, Nov 29 2018
%o (Magma) &cat [[3, 6]^^50]; // _Vincenzo Librandi_, Feb 28 2020
%Y Cf. A000034, A007283, A176105, A213999.
%K nonn,easy
%O 0,1
%A _N. J. A. Sloane_