%I #52 Mar 05 2024 11:25:03
%S 2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,
%T 2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,2,5,
%U 2,5,2,5,2,5,2,5,2,5,2,5,2
%N Period 2: repeat (2,5).
%C Also decimal expansion of 25/99.
%C Continued fraction expansion of A176052. - _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 G.f.: (2+5*x)/((1-x)*(1+x)). - _R. J. Mathar_, Nov 21 2011
%F a(n) = 2^(1-(-1)^n) + 1. [_Bruno Berselli_, Dec 29 2015]
%F From _Nicolas Bělohoubek_, Nov 11 2021: (Start)
%F a(n) = 10/a(n-1). See also A010691.
%F a(n) = 7 - a(n-1). See also A010702. (End)
%o (Maxima) makelist(if evenp(n) then 2 else 5, n, 0, 80); /* _Martin Ettl_, Nov 09 2012 */
%o (Magma) &cat [[2,5]^^50]; // _Bruno Berselli_, Dec 29 2015
%Y Cf. A010674 (2^(1-(-1)^n) - 1).
%Y Cf. A010691.
%K nonn,easy
%O 0,1
%A _N. J. A. Sloane_.
%E Edited by _Bruno Berselli_, Dec 29 2015