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 A189968 #14 Sep 08 2022 08:45:56
%S A189968 2,3,6,9,9,2,4,0,7,6,2,1,5,4,8,1,2,1,8,3,3,3,7,1,2,3,8,0,2,9,3,7,9,8,
%T A189968 8,5,9,5,4,1,1,3,4,1,7,4,7,8,7,0,7,7,3,3,4,6,6,7,9,5,8,7,0,0,9,0,7,1,
%U A189968 1,1,8,3,7,8,0,0,3,1,2,5,7,6,7,9,4,6,4,9,0,1,5,1,3,2,2,1,3,4,2,7,4,9,0,0,5,6,6,3,4,8,1,3,1,4,5,2,8,0,6,9
%N A189968 Decimal expansion of (5+sqrt(85))/6, which has periodic continued fractions [2,2,1,2,2,1,...] and [5/2, 1, 5/2, 1, ...].
%C A189968 Let R denote a rectangle whose shape (i.e., length/width) is (5+sqrt(85))/6. This rectangle can be partitioned into squares in a manner that matches the continued fraction [2,2,1,2,2,1,...]. It can also be partitioned into rectangles of shape 3/2 and 3 so as to match the continued fraction [5/2, 1, 5/2, 1, ...]. For details, see A188635.
%H A189968 G. C. Greubel, <a href="/A189968/b189968.txt">Table of n, a(n) for n = 1..10000</a>
%e A189968 2.369924076215481218333712380293798859541...
%t A189968 FromContinuedFraction[{5/2, 1, {5/2, 1}}]
%t A189968 ContinuedFraction[%, 25] (* [2,2,1,2,2,1,...] *)
%t A189968 RealDigits[N[%%, 120]] (* A189967 *)
%t A189968 N[%%%, 40]
%t A189968 RealDigits[(5+Sqrt[85])/6,10,120][[1]] (* _Harvey P. Dale_, Apr 18 2014 *)
%o A189968 (PARI) (5+sqrt(85))/6 \\ _G. C. Greubel_, Jan 12 2018
%o A189968 (Magma) (5+Sqrt(85))/6 // _G. C. Greubel_, Jan 12 2018
%Y A189968 Cf. A188635, A189966.
%K A189968 nonn,cons
%O A189968 1,1
%A A189968 _Clark Kimberling_, May 05 2011