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 A021554 #20 Jul 08 2025 08:36:24
%S A021554 0,0,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,
%T A021554 1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,
%U A021554 1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1,8,1
%N A021554 Decimal expansion of 1/550.
%C A021554 A021059 shifted right, A010689 shifted right twice. [From _R. J. Mathar_, Oct 25 2008]
%H A021554 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (0,1).
%t A021554 realDigitsRecip[550] (* The realDigitsRecip program is at A021200 *) (* or *) PadRight[{0,0},120,{1,8}] (* _Harvey P. Dale_, Dec 28 2024 *)
%o A021554 (PARI) { default(realprecision); x=1/550*10; for(n=1, 100, d=floor(x); x=(x-d)*10; print1(d, ", ")) } \\ _Felix Fröhlich_, Aug 11 2014
%K A021554 nonn,cons
%O A021554 0,4
%A A021554 _N. J. A. Sloane_