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 A269222 #26 Sep 03 2022 23:41:30
%S A269222 1,9,8,9,1,9,8,9,1,9,8,9,1,9,8,9,1,9,8,9,1,9,8,9,1,9,8,9,1,9,8,9,1,9,
%T A269222 8,9,1,9,8,9,1,9,8,9,1,9,8,9,1,9,8,9,1,9,8,9,1,9,8,9,1,9,8,9,1,9,8,9,
%U A269222 1,9,8,9,1,9,8,9,1,9,8,9,1,9,8,9,1,9,8,9
%N A269222 Period 4: repeat [1,9,8,9].
%C A269222 Digital root of Fib(18*n).
%C A269222 Decimal expansion of 221/1111.
%H A269222 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,1).
%F A269222 a(n) = A010888(Fibonacci(18*n)).
%F A269222 From _Wesley Ivan Hurt_, Sep 03 2022: (Start)
%F A269222 a(n) = a(n-4) for n >= 5.
%F A269222 a(n) = (9/4)*(3+(-1)^n)-7*sin(n*Pi/2)/2. (End)
%e A269222 For n=2, a(2) = digital root of Fibonacci(18*2) or 14930352; therefore, a(2) = 9, since the digital root of 14930352 = 9.
%t A269222 Table[NestWhile[Total@ IntegerDigits@ # &, Fibonacci[18 n], IntegerLength@ # > 1 &], {n, 120}] (* _Michael De Vlieger_, Jul 11 2016 *)
%t A269222 PadRight[{},100,{1,9,8,9}] (* _Harvey P. Dale_, Sep 24 2021 *)
%o A269222 (PARI) a(n)=[9,1,9,8][n%4+1] \\ _Charles R Greathouse IV_, Jul 21 2016
%Y A269222 Cf. A008600, A010888.
%K A269222 nonn,base,easy
%O A269222 1,2
%A A269222 _Peter M. Chema_, Jul 11 2016