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 A089012 #13 Oct 13 2017 05:53:49
%S A089012 1,0,0,1,1,0,1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%T A089012 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%U A089012 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
%N A089012 a(n) = 1 if n is an exponent of the Weyl group W(E_6), 0 otherwise.
%C A089012 The exponents are 1, 4, 5, 7, 8, 11. The point of this sequence is that a similar generating function gives the exponents for any finite Coxeter group.
%H A089012 Antti Karttunen, <a href="/A089012/b089012.txt">Table of n, a(n) for n = 1..1001</a>
%H A089012 <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%F A089012 G.f.: (1-x^8)*(1-x^9)/((1-x^3)*(1-x^4)).
%t A089012 CoefficientList[Series[(1 - x^8) (1 - x^9)/((1 - x^3) (1 - x^4)), {x, 0, 11}], x] (* _Michael De Vlieger_, Oct 10 2017 *)
%o A089012 (Scheme) (define (A089012 n) (if (member n '(1 4 5 7 8 11)) 1 0)) ;; _Antti Karttunen_, Oct 10 2017
%Y A089012 Characteristic function of A005556.
%K A089012 easy,nonn
%O A089012 1,1
%A A089012 _Paul Boddington_, Nov 03 2003
%E A089012 More zeros from _Antti Karttunen_, Oct 10 2017