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 A190256 #16 Sep 08 2022 08:45:57
%S A190256 2,2,7,1,2,8,1,5,6,2,4,2,2,9,9,4,1,4,2,3,1,3,0,5,8,0,6,8,7,5,9,7,2,6,
%T A190256 8,5,5,4,5,5,8,4,9,2,6,9,1,0,2,1,4,3,4,3,2,8,7,4,9,0,8,2,8,2,6,5,9,1,
%U A190256 6,4,3,9,1,5,4,3,9,2,2,1,2,3,6,1,6,7,1,5,1,8,5,5,1,0,2,9,6,0,3,1,3,7,3,1,9,7,0,3,3,5,9,4,8,5,3,0,0,5,2,6
%N A190256 Decimal expansion of sqrt((3 + x + sqrt(9+6x))/2), where x=sqrt(6).
%C A190256 The rectangle R whose shape (i.e., length/width) is sqrt(3+x+sqrt(9+6x)), where x=sqrt(6), can be partitioned into rectangles of shapes sqrt(3) and sqrt(2) in a manner that matches the periodic continued fraction [sqrt(3), sqrt(2), sqrt(3), sqrt(2), ...]. R can also be partitioned into squares so as to match the nonperiodic continued fraction [2,3,1,2,5,2,1,5,95,1,...] at A190257. For details, see A188635.
%H A190256 G. C. Greubel, <a href="/A190256/b190256.txt">Table of n, a(n) for n = 1..10000</a>
%e A190256 2.271281562422994142313058068759726855455...
%t A190256 FromContinuedFraction[{3^(1/2), 2^(1/2), {3^(1/2), 2^(1/2)}}]
%t A190256 FullSimplify[%]
%t A190256 ContinuedFraction[%, 100] (* A190256 *)
%t A190256 RealDigits[N[%%, 120]] (* A190257 *)
%t A190256 N[%%%, 40]
%o A190256 (PARI) sqrt((3+sqrt(6)+sqrt(9+6*sqrt(6)))/2) \\ _G. C. Greubel_, Dec 26 2017
%o A190256 (Magma) [Sqrt((3+Sqrt(6)+Sqrt(9+6*Sqrt(6)))/2)]; // _G. C. Greubel_, Dec 26 2017
%Y A190256 Cf. A190256, A190184, A190185.
%K A190256 nonn,cons
%O A190256 1,1
%A A190256 _Clark Kimberling_, May 06 2011
%E A190256 Name corrected by _T. D. Noe_, Feb 25 2013