%I #24 Dec 14 2023 06:04:08
%S 3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,
%T 3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,3,9,
%U 3,9,3,9,3,9,3,9,3,9,3,9,3
%N Period 2: repeat (3,9).
%C Continued fraction expansion of A176108. - _R. J. Mathar_, Mar 08 2012
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (0,1).
%F a(n) = -3*(-1)^n+6. - _Paolo P. Lava_, Oct 20 2006
%F G.f.: 3(1+3x)/((1-x)(1+x)). - _R. J. Mathar_, Nov 21 2011
%t PadRight[{},120,{3,9}] (* _Harvey P. Dale_, Nov 07 2017 *)
%o (PARI) a(n)=3+n%2*6 \\ _Charles R Greathouse IV_, Dec 21 2011
%K nonn,easy
%O 0,1
%A _N. J. A. Sloane_.