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A021031 Decimal expansion of 1/27.

%I A021031 #18 Jul 08 2025 07:57:59
%S A021031 0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,
%T A021031 3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,
%U A021031 7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7,0,3,7
%N A021031 Decimal expansion of 1/27.
%H A021031 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 1).
%F A021031 From _Bruno Berselli_, Sep 24 2010: (Start)
%F A021031 G.f.: x*(3+7*x)/(1-x^3).
%F A021031 a(n) - a(n-3) = 0 for n > 2.
%F A021031 a(n) = A175833(n) - 4 = 4*(n-3*floor(n/3)) - (1 - (-1)^(n-3*floor((n+1)/3)))/2.
%F A021031  (End)
%e A021031 0.037037037037037037037037037037037037037...
%t A021031 RealDigits[1/27, 10, 108][[1]] (* _Alonso del Arte_, Feb 26 2015 *)
%K A021031 nonn,cons,easy
%O A021031 0,2
%A A021031 _N. J. A. Sloane_