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 A021217 #12 Jul 13 2025 18:23:07
%S A021217 0,0,4,6,9,4,8,3,5,6,8,0,7,5,1,1,7,3,7,0,8,9,2,0,1,8,7,7,9,3,4,2,7,2,
%T A021217 3,0,0,4,6,9,4,8,3,5,6,8,0,7,5,1,1,7,3,7,0,8,9,2,0,1,8,7,7,9,3,4,2,7,
%U A021217 2,3,0,0,4,6,9,4,8,3,5,6,8,0,7,5,1,1,7,3,7,0,8,9,2,0,1,8,7,7,9
%N A021217 Decimal expansion of 1/213.
%C A021217 Periodic with period length = 35. - _Harvey P. Dale_, Jan 15 2023
%H A021217 <a href="/index/Rec#order_35">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1).
%t A021217 Join[{0,0},RealDigits[1/213,10,120][[1]]] (* or *) PadRight[{},120, {0,0,4,6,9,4,8,3,5,6, 8,0,7,5,1,1,7,3,7,0,8,9,2,0,1,8,7, 7,9,3,4,2,7,2,3}] (* _Harvey P. Dale_, Jan 15 2023 *)
%t A021217 realDigitsRecip[213] (* The realDigitsRecip program is at A021200 *) (* _Harvey P. Dale_, Aug 26 2024 *)
%K A021217 nonn,cons
%O A021217 0,3
%A A021217 _N. J. A. Sloane_