A021721 - OEIS

%I #16 Sep 02 2025 18:22:31

%S 0,0,1,3,9,4,7,0,0,1,3,9,4,7,0,0,1,3,9,4,7,0,0,1,3,9,4,7,0,0,1,3,9,4,

%T 7,0,0,1,3,9,4,7,0,0,1,3,9,4,7,0,0,1,3,9,4,7,0,0,1,3,9,4,7,0,0,1,3,9,

%U 4,7,0,0,1,3,9,4,7,0,0,1,3,9,4,7,0,0,1,3,9,4,7,0,0,1,3,9,4,7,0

%N Decimal expansion of 1/717.

%H <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,1).

%F From _Chai Wah Wu_, Apr 22 2024: (Start)

%F a(n) = a(n-7) for n > 6.

%F G.f.: x^2*(-7*x^4 - 4*x^3 - 9*x^2 - 3*x - 1)/(x^7 - 1). (End)

%e 0.00139470013947001394700139470013947...

%t First[RealDigits[1/717, 10, 100, -1]] (* _Paolo Xausa_, Sep 02 2025 *)

%K nonn,cons,easy

%O 0,4

%A _N. J. A. Sloane_