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 A147674 #13 Dec 12 2023 08:13:09
%S A147674 81,27,9,27,27,9,27,81,9,81,27,9,27,27,9,27,81,9,81,27,9,27,27,9,27,
%T A147674 81,9,81,27,9,27,27,9,27,81,9
%N A147674 Period 9: repeat 81,27,9,27,27,9,27,81,9.
%H A147674 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 1).
%t A147674 PadRight[{},120,{81,27,9,27,27,9,27,81,9}] (* _Harvey P. Dale_, Jun 27 2020 *)
%K A147674 nonn,less
%O A147674 0,1
%A A147674 _Paul Curtz_, Nov 10 2008