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 A161016 #13 May 14 2019 21:35:45
%S A161016 1,4,3,8,3,6,9,5,9,4,3,6,1,9,0,9,3,5,2,8,0,0,3,0,5,9,9,1,3,5,6,2,3,3,
%T A161016 4,4,9,8,7,5,6,8,1,6,9,6,7,3,8,8,8,5,3,9,3,3,0,8,7,1,0,0,1,6,5,3,1,8,
%U A161016 6,4,4,4,9,9,4,6,1,4,5,3,6,3,4,8,4,9,8,7,3,6,8,3,9,2,6,8,2,6,8,4,3,9,5,4,5
%N A161016 Decimal expansion of tan(1/7).
%C A161016 By the Lindemann-Weierstrass theorem, this constant is transcendental. - _Charles R Greathouse IV_, May 13 2019
%H A161016 Harry J. Smith, <a href="/A161016/b161016.txt">Table of n, a(n) for n = 0..20000</a>
%H A161016 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>
%e A161016 0.143836959436190935280030599135623344987568169673888539330871001653186...
%t A161016 RealDigits[Tan[1/7],10,120][[1]] (* _Harvey P. Dale_, Dec 11 2016 *)
%o A161016 (PARI) default(realprecision, 20080); x=10*tan(1/7); for (n=0, 20000, d=floor(x); x=(x-d)*10; write("b161016.txt", n, " ", d));
%Y A161016 Cf. A019430 Continued fraction.
%K A161016 cons,nonn
%O A161016 0,2
%A A161016 _Harry J. Smith_, Jun 14 2009