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 A156227 #18 Dec 15 2023 17:13:52
%S A156227 0,1,3,8,3,1,0,8,6,1,6,8,0,1,3,8,3,1,0,8,6,1,6,8,0,1,3,8,3,1,0,8,6,1,
%T A156227 6,8,0,1,3,8,3,1,0,8,6,1,6,8,0,1,3,8,3,1,0,8,6,1,6,8,0,1,3,8,3,1,0,8,
%U A156227 6,1,6,8,0,1,3,8,3,1,0,8,6,1,6,8,0,1,3,8,3,1,0,8,6,1,6,8,0,1,3,8,3
%N A156227 Period 12: repeat [0,1,3,8,3,1,0,8,6,1,6,8].
%H A156227 <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).
%F A156227 a(n) = a(n-12). - _Wesley Ivan Hurt_, May 24 2021
%t A156227 LinearRecurrence[{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},{0, 1, 3, 8, 3, 1, 0, 8, 6, 1, 6, 8},48] (* _Ray Chandler_, Aug 08 2015 *)
%t A156227 PadRight[{},120,{0,1,3,8,3,1,0,8,6,1,6,8}] (* _Harvey P. Dale_, Dec 15 2023 *)
%o A156227 (PARI) a(n)=[0,1,3,8,3,1,0,8,6,1,6,8][n%12+1] \\ _Charles R Greathouse IV_, Jul 13 2016
%K A156227 nonn,easy
%O A156227 0,3
%A A156227 _Paul Curtz_, Feb 06 2009