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 A016704 #28 Sep 08 2022 08:44:41
%S A016704 4,3,9,4,4,4,9,1,5,4,6,7,2,4,3,8,7,6,5,5,8,0,9,8,0,9,4,7,6,9,0,1,0,2,
%T A016704 8,1,8,5,8,9,9,6,2,2,3,1,2,9,0,9,9,7,8,0,6,9,3,8,7,7,7,3,3,4,5,4,9,9,
%U A016704 7,7,1,7,2,8,7,4,4,3,5,8,6,7,4,9,4,4,6,3,0,1,9,2,5,4,9,2,8,3,5
%N A016704 Decimal expansion of log(81).
%H A016704 Harry J. Smith, <a href="/A016704/b016704.txt">Table of n, a(n) for n = 1..20000</a>
%H A016704 M. Abramowitz and I. A. Stegun, eds., <a href="http://www.convertit.com/Go/ConvertIt/Reference/AMS55.ASP">Handbook of Mathematical Functions</a>, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
%H A016704 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>
%F A016704 2 times A016632.
%e A016704 4.394449154672438765580980947690102818589962231290997806938777334549977....
%t A016704 RealDigits[Log[81],10,120][[1]] (* _Harvey P. Dale_, Feb 20 2012 *)
%o A016704 (PARI) default(realprecision, 20080); x=log(81); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b016704.txt", n, " ", d)); \\ _Harry J. Smith_, May 24 2009
%o A016704 (Magma) SetDefaultRealField(RealField(100)); Log(81); // _G. C. Greubel_, Sep 17 2018
%Y A016704 Cf. A016509 (continued fraction).
%K A016704 nonn,cons
%O A016704 1,1
%A A016704 _N. J. A. Sloane_