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 A037619 #11 Feb 13 2017 02:54:08
%S A037619 2,10,53,267,1335,6678,33392,166960,834803,4174017,20870085,104350428,
%T A037619 521752142,2608760710,13043803553,65219017767,326095088835,
%U A037619 1630475444178,8152377220892,40761886104460,203809430522303,1019047152611517
%N A037619 Base 5 digits are, in order, the first n terms of the periodic sequence with initial period 2,0,3.
%H A037619 <a href="/index/Ar#5-automatic">Index entries for 5-automatic sequences</a>.
%H A037619 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (5,0,1,-5).
%F A037619 G.f.: x*(2+3*x^2) / ( (x-1)*(5*x-1)*(1+x+x^2) ). - _R. J. Mathar_, Apr 27 2015
%F A037619 A007091(a(n)) = A037624(n). - _R. J. Mathar_, Apr 27 2015
%t A037619 nn=30;With[{c=PadRight[{},nn,{2,0,3}]},Table[FromDigits[Take[c,n],5],{n,nn}]] (* _Harvey P. Dale_, Aug 29 2012 *)
%o A037619 (PARI) a(n)=([0,1,0,0; 0,0,1,0; 0,0,0,1; -5,1,0,5]^(n-1)*[2;10;53;267])[1,1] \\ _Charles R Greathouse IV_, Feb 13 2017
%K A037619 nonn,base,easy
%O A037619 1,1
%A A037619 _Clark Kimberling_