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 A275615 #19 Oct 05 2018 08:00:51
%S A275615 1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,
%T A275615 9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,
%U A275615 8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8,1,9,8
%N A275615 Decimal expansion of 22/111.
%C A275615 Period 3: repeat [1,9,8]. Also the digital root of Nexus numbers A022522.
%C A275615 Other variants of this period are decimal expansions of 91/111 (.819 repeating) and 109/111 (.981 repeating).
%F A275615 a(n) = A010888(A022522(n)).
%F A275615 a(n) = 6 - 5*cos(2*n*Pi/3) + sin(2*n*Pi/3)/sqrt(3). - _Wesley Ivan Hurt_, Oct 04 2018
%e A275615 0.198198198198198198198198198198198198198198198198198198198...
%t A275615 First@ RealDigits@ N[22/111, 120] (* or *)
%t A275615 PadRight[{}, 120, {1, 9, 8}] (* or *)
%t A275615 FixedPoint[Total@ IntegerDigits@ # &, #] & /@ Table[(n + 1)^6 - n^6, {n, 0, 120}] (* _Michael De Vlieger_, Aug 04 2016 *)
%o A275615 (PARI) a(n) = my(x=[1, 9, 8]); x[n%3+1] \\ _Felix Fröhlich_, Aug 04 2016
%Y A275615 Cf. A010888, A022522.
%K A275615 nonn,cons,easy
%O A275615 0,2
%A A275615 _Peter M. Chema_, Aug 03 2016