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 A153186 #17 Mar 02 2024 01:27:35
%S A153186 1,7,4,7,4,7,1,1,1,1,7,4,7,4,7,1,1,1,1,7,4,7,4,7,1,1,1,1,7,4,7,4,7,1,
%T A153186 1,1,1,7,4,7,4,7,1,1,1,1,7,4,7,4,7,1,1,1,1,7,4,7,4,7,1,1,1,1,7,4,7,4,
%U A153186 7,1,1,1
%N A153186 Period 9: repeat 1,7,4,7,4,7,1,1,1.
%H A153186 <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 A153186 PadRight[{},120,{1,7,4,7,4,7,1,1,1}] (* _Harvey P. Dale_, Sep 14 2019 *)
%o A153186 (PARI) a(n)=[1,7,4,7,4,7,1,1,1][n%9+1] \\ _Charles R Greathouse IV_, Jul 13 2016
%Y A153186 Cf. A046163.
%K A153186 nonn,easy
%O A153186 0,2
%A A153186 _Paul Curtz_, Dec 20 2008
%E A153186 Edited by _N. J. A. Sloane_, Dec 25 2008