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 A138055 #24 Feb 27 2024 03:04:29
%S A138055 1,3,5,9,3,1,9,5,1,3,5,9,3,1,9,5,1,3,5,9,3,1,9,5,1,3,5,9,3,1,9,5,1,3,
%T A138055 5,9,3,1,9,5,1,3,5,9,3,1,9,5,1,3,5,9,3,1,9,5,1,3,5,9,3,1,9,5,1,3,5,9,
%U A138055 3,1,9,5,1,3,5,9,3,1,9,5,1,3,5,9,3,1,9,5,1,3,5,9,3,1,9,5,1,3,5,9,3,1,9,5,1
%N A138055 Period 8: repeat 1, 3, 5, 9, 3, 1, 9, 5.
%H A138055 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (1,-1,1,-1,1,-1,1).
%t A138055 PadRight[{},120,{1,3,5,9,3,1,9,5}] (* _Harvey P. Dale_, Apr 13 2019 *)
%o A138055 (PARI) a(n)=[1,3,5,9,3,1,9,5][n%8+1] \\ _Charles R Greathouse IV_, Jun 02 2011
%Y A138055 Cf. A136252.
%K A138055 nonn,easy,less
%O A138055 0,2
%A A138055 _Paul Curtz_, May 02 2008