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 A091687 #8 Jun 22 2020 07:03:33 %S A091687 1,2,7,60,3444,11402948,129187106461769 %N A091687 Number of lattice congruences of the weak order on the Coxeter group S_n (the symmetric group). %C A091687 To a very good approximation for n=4,5,6 we have a(n+1) ~ (a(n))^2. %H A091687 Nathan Reading, <a href="http://arXiv.org/abs/math.CO/0401404">Lattice congruences of the weak order</a>, arXiv:math/0401404 [math.CO], 2004. %Y A091687 Cf. A091688, A330039. %K A091687 nonn,hard,more %O A091687 1,2 %A A091687 Nathan Reading (nreading(AT)umich.edu), Jan 28 2004