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 A161014 #11 Aug 26 2019 13:33:50
%S A161014 2,0,2,7,1,0,0,3,5,5,0,8,6,7,2,4,8,3,3,2,1,3,5,8,2,7,1,6,4,7,5,3,4,4,
%T A161014 8,2,6,2,6,8,7,5,6,6,9,6,5,1,6,3,1,3,3,0,0,4,7,8,1,9,9,6,6,8,9,0,3,8,
%U A161014 2,1,8,5,0,0,1,9,9,9,7,0,0,0,9,1,1,7,3,9,0,0,8,9,2,6,2,1,4,4,2,7,2,3,0,4,7
%N A161014 Decimal expansion of tan(1/5).
%C A161014 By the Lindemann-Weierstrass theorem, this constant is transcendental. - _Charles R Greathouse IV_, May 13 2019
%H A161014 Harry J. Smith, <a href="/A161014/b161014.txt">Table of n, a(n) for n = 0..20000</a>
%H A161014 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>
%e A161014 0.202710035508672483321358271647534482626875669651631330047819966890382...
%t A161014 RealDigits[Tan[1/5],10,120][[1]] (* _Harvey P. Dale_, Aug 26 2019 *)
%o A161014 (PARI) default(realprecision, 20080); x=10*tan(1/5); for (n=0, 20000, d=floor(x); x=(x-d)*10; write("b161014.txt", n, " ", d));
%Y A161014 Cf. A019428 Continued fraction.
%K A161014 cons,nonn
%O A161014 0,1
%A A161014 _Harry J. Smith_, Jun 13 2009