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 A161013 #11 May 23 2019 14:09:40
%S A161013 2,5,5,3,4,1,9,2,1,2,2,1,0,3,6,2,6,6,5,0,4,4,8,2,2,3,6,4,9,0,4,7,3,6,
%T A161013 7,8,2,0,4,2,0,1,6,3,8,8,0,0,8,2,2,6,2,1,7,4,0,4,7,5,6,5,0,2,5,8,8,8,
%U A161013 3,1,9,8,1,3,4,6,5,4,2,5,7,9,4,9,3,1,6,5,0,2,6,3,1,0,5,5,0,4,5,3,9,6,4,1,1
%N A161013 Decimal expansion of tan(1/4).
%C A161013 By the Lindemann-Weierstrass theorem, this constant is transcendental. - _Charles R Greathouse IV_, May 13 2019
%H A161013 Harry J. Smith, <a href="/A161013/b161013.txt">Table of n, a(n) for n = 0..20000</a>
%H A161013 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>
%e A161013 0.255341921221036266504482236490473678204201638800822621740475650258883...
%t A161013 RealDigits[Tan[1/4],10,120][[1]] (* _Harvey P. Dale_, May 23 2019 *)
%o A161013 (PARI) default(realprecision, 20080); x=10*tan(1/4); for (n=0, 20000, d=floor(x); x=(x-d)*10; write("b161013.txt", n, " ", d));
%Y A161013 Cf. A019427 Continued fraction.
%K A161013 cons,nonn
%O A161013 0,1
%A A161013 _Harry J. Smith_, Jun 13 2009