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 A161012 #13 Jun 27 2023 03:20:31
%S A161012 3,4,6,2,5,3,5,4,9,5,1,0,5,7,5,4,9,1,0,3,8,5,4,3,5,6,5,6,0,9,7,4,0,7,
%T A161012 7,4,5,9,5,7,0,3,9,1,6,1,8,9,8,0,0,2,1,7,9,7,6,4,4,4,0,6,4,8,9,8,5,9,
%U A161012 7,6,5,7,4,9,1,5,4,7,5,5,2,8,1,5,9,6,5,7,8,7,0,0,9,3,9,7,2,6,6,9,0,5,0,4,9
%N A161012 Decimal expansion of tan(1/3).
%C A161012 By the Lindemann-Weierstrass theorem, this constant is transcendental. - _Charles R Greathouse IV_, May 13 2019
%H A161012 Harry J. Smith, <a href="/A161012/b161012.txt">Table of n, a(n) for n = 0..20000</a>
%H A161012 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A161012 0.346253549510575491038543565609740774595703916189800217976444064898597...
%t A161012 RealDigits[Tan[1/3], 10, 120][[1]] (* _Amiram Eldar_, Jun 27 2023 *)
%o A161012 (PARI) default(realprecision, 20080); x=10*tan(1/3); for (n=0, 20000, d=floor(x); x=(x-d)*10; write("b161012.txt", n, " ", d));
%Y A161012 Cf. A019426 (continued fraction).
%K A161012 cons,nonn
%O A161012 0,1
%A A161012 _Harry J. Smith_, Jun 13 2009