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 A161015 #11 May 14 2019 21:35:47
%S A161015 1,6,8,2,2,7,2,1,8,3,0,2,2,4,2,4,6,1,2,5,7,2,1,6,0,8,0,5,6,9,9,1,6,1,
%T A161015 0,0,9,6,9,3,9,3,6,5,1,6,8,5,0,5,6,6,8,5,7,2,4,0,3,2,7,3,9,2,4,8,2,4,
%U A161015 7,4,3,8,7,0,8,5,3,1,6,1,6,3,2,7,9,4,4,9,8,1,3,5,1,8,3,5,7,3,0,3,9,2,8,1,5
%N A161015 Decimal expansion of tan(1/6).
%C A161015 By the Lindemann-Weierstrass theorem, this constant is transcendental. - _Charles R Greathouse IV_, May 13 2019
%H A161015 Harry J. Smith, <a href="/A161015/b161015.txt">Table of n, a(n) for n = 0..20000</a>
%H A161015 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>
%e A161015 0.168227218302242461257216080569916100969393651685056685724032739248247...
%t A161015 RealDigits[Tan[1/6],10,120][[1]] (* _Harvey P. Dale_, Aug 26 2014 *)
%o A161015 (PARI) default(realprecision, 20080); x=10*tan(1/6); for (n=0, 20000, d=floor(x); x=(x-d)*10; write("b161015.txt", n, " ", d));
%Y A161015 Cf. A019429 Continued fraction.
%K A161015 cons,nonn
%O A161015 0,2
%A A161015 _Harry J. Smith_, Jun 13 2009