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 A010475 #15 Aug 21 2023 11:16:27
%S A010475 4,3,5,8,8,9,8,9,4,3,5,4,0,6,7,3,5,5,2,2,3,6,9,8,1,9,8,3,8,5,9,6,1,5,
%T A010475 6,5,9,1,3,7,0,0,3,9,2,5,2,3,2,4,4,4,9,3,6,8,9,0,3,4,4,1,3,8,1,5,9,5,
%U A010475 5,7,3,2,8,2,0,3,1,5,8,0,8,5,6,5,6,1,5,9,1,5,5,8,5,1,9,4,4,5,2
%N A010475 Decimal expansion of square root of 19.
%C A010475 Continued fraction expansion is 4 followed by {2, 1, 3, 1, 2, 8} repeated. - _Harry J. Smith_, Jun 03 2009
%H A010475 Harry J. Smith, <a href="/A010475/b010475.txt">Table of n, a(n) for n = 1..20000</a>
%H A010475 <a href="/index/Al#algebraic_02">Index entries for algebraic numbers, degree 2</a>
%e A010475 4.358898943540673552236981983859615659137003925232444936890344138159557....
%t A010475 RealDigits[N[Sqrt[19],200]][[1]] (* _Vladimir Joseph Stephan Orlovsky_, Feb 21 2011 *)
%o A010475 (PARI) default(realprecision, 20080); x=sqrt(19); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b010475.txt", n, " ", d)); \\ _Harry J. Smith_, Jun 03 2009
%Y A010475 Cf. A010124 (continued fraction).
%K A010475 nonn,cons
%O A010475 1,1
%A A010475 _N. J. A. Sloane_