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 A037512 #15 Jun 30 2022 11:55:37
%S A037512 2,6,19,59,177,532,1598,4794,14383,43151,129453,388360,1165082,
%T A037512 3495246,10485739,31457219,94371657,283114972,849344918,2548034754,
%U A037512 7644104263,22932312791,68796938373,206390815120,619172445362
%N A037512 Base 3 digits are, in order, the first n terms of the periodic sequence with initial period 2,0,1.
%H A037512 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (3,0,1,-3).
%F A037512 G.f.: x*(2+x^2) / ( (x-1)*(3*x-1)*(1+x+x^2) ). - _R. J. Mathar_, Nov 21 2011
%t A037512 Table[FromDigits[PadRight[{},n,{2,0,1}],3],{n,30}] (* or *) LinearRecurrence[{3,0,1,-3},{2,6,19,59},30] (* _Harvey P. Dale_, Jun 30 2022 *)
%K A037512 nonn,base
%O A037512 1,1
%A A037512 _Clark Kimberling_