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 A133390 #18 Dec 12 2023 08:53:33
%S A133390 1,4,7,2,2,5,4,1,1,8,5,2,7,7,4,5,8,8,1,4,7,2,2,5,4,1,1,8,5,2,7,7,4,5,
%T A133390 8,8,1,4,7,2,2,5,4,1,1,8,5,2,7,7,4,5,8,8,1,4,7,2,2,5,4,1,1,8,5,2,7,7,
%U A133390 4,5,8,8,1,4,7,2,2,5,4,1,1,8,5,2,7,7,4,5,8,8
%N A133390 Period 18: repeat 1, 4, 7, 2, 2, 5, 4, 1, 1, 8, 5, 2, 7, 7, 4, 5, 8, 8.
%C A133390 Disordered, three times 1, 2, 4, 5, 7, 8.
%H A133390 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,0,0,0,0,0,-1,1).
%F A133390 Sum of digits mod 9 of 1, 4, 7, 11, 20, A130625. Digits of 1/7, A020806 or A029898, 1, 1, 2, 4, 8.
%t A133390 PadRight[{},18*5,{1,4,7,2,2,5,4,1,1,8,5,2,7,7,4,5,8,8}] (* _Harvey P. Dale_, Nov 06 2011 *)
%o A133390 (PARI) for(i=1,9,print1("1, 4, 7, 2, 2, 5, 4, 1, 1, 8, 5, 2, 7, 7, 4, 5, 8, 8, ")) \\ _Charles R Greathouse IV_, Jun 02 2011
%K A133390 nonn,easy,less
%O A133390 0,2
%A A133390 _Paul Curtz_, Nov 23 2007