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 A154473 #6 Jun 02 2025 01:17:50
%S A154473 842,11090,13202,46882,60994,231272004,198873570440,266349291297936,
%T A154473 64442911458703648,3667589230123774528,3336154829743802737792,
%U A154473 17601566387699271821281536,1023499990310357893964861952
%N A154473 a(n) = A014486(A154472(n)).
%C A154473 This sequence gives the parenthesis expressions shown at the upper right corner image of the page 103 of NKS, with the left brackets (black squares) converted to 1's and the right brackets (white squares) converted to 0's and then interpreting each such number as a binary number and converted to decimal. A154474 shows the corresponding binary representations. Compare to A080070, A122242, A122245.
%H A154473 A. Karttunen and W. Meeussen, <a href="/A154473/b154473.txt">Table of n, a(n) for n = 0..100</a>
%H A154473 S. Wolfram, <a href="http://www.wolframscience.com/nksonline/page-102">A New Kind of Science, Wolfram Media Inc., (2002), p. 102</a>, <a href="http://www.wolframscience.com/nksonline/page-103">p. 103</a> and pages 104, 896-898.
%t A154473 init=e[e[e][e]][e][e]
%t A154473 toDeca[ w_ ]:=FromDigits[ ToExpression[ Characters[ ToString[ w ] ]/.{"e"->Sequence[], "["->"1","]"->"0"} ],2 ]
%t A154473 toDeca /@ NestList[ #/.e[x_ ][y_ ]->x[x[y]]&, init, 100]
%Y A154473 Cf. A154475, A154476.
%K A154473 nonn,base
%O A154473 0,1
%A A154473 _Antti Karttunen_, with terms a(0)-a(100) also independently computed by _Wouter Meeussen_, with the given Mathematica program, Jan 11 2009