This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A021559 #33 Feb 22 2024 09:04:33
%S A021559 0,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,
%T A021559 0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,
%U A021559 1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1,8,0,1
%N A021559 Decimal expansion of 1/555.
%H A021559 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,1).
%F A021559 a(n) = (n+2)^3 mod 9, n>0. - _Gary Detlefs_, Feb 20 2011
%F A021559 G.f.: x^2*(1 + 8*x)/(1 - x^3). - _Ilya Gutkovskiy_, Jun 04 2016
%e A021559 0.00180180180180180180180180180180180...
%t A021559 PadRight[{0}, 100, {8, 0, 1}] (* _Paolo Xausa_, Feb 22 2024 *)
%o A021559 (PARI) 1/555.0 \\ _Michel Marcus_, Jun 04 2016
%K A021559 nonn,cons
%O A021559 0,4
%A A021559 _N. J. A. Sloane_
%E A021559 Formula corrected by _Paolo P. Lava_, Nov 20 2009