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 A267387 #7 Feb 18 2017 08:36:50 %S A267387 1,1,2,6,24,120,720,5040,35280,287280,2656080,27422640,312273360, %T A267387 3884393520,52370755920,704126188080,10259633739600,160825241006640, %U A267387 2696186419390800,48104638617656880,909616190783645520,18163810790066314800,361758057531039101520 %N A267387 Number of acyclic orientations of the Turán graph T(n,7). %C A267387 An acyclic orientation is an assignment of a direction to each edge such that no cycle in the graph is consistently oriented. Stanley showed that the number of acyclic orientations of a graph G is equal to the absolute value of the chromatic polynomial X_G(q) evaluated at q=-1. %H A267387 Alois P. Heinz, <a href="/A267387/b267387.txt">Table of n, a(n) for n = 0..450</a> %H A267387 Richard P. Stanley, <a href="http://dx.doi.org/10.1016/0012-365X(73)90108-8">Acyclic Orientations of Graphs</a>, Discrete Mathematics, 5 (1973), pages 171-178, doi:10.1016/0012-365X(73)90108-8 %H A267387 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tur%C3%A1n_graph">Turán graph</a> %F A267387 a(n) ~ n! / (6 * (1 - log(7/6))^3 * 7^n * (log(7/6))^(n+1)). - _Vaclav Kotesovec_, Feb 18 2017 %Y A267387 Column k=7 of A267383. %K A267387 nonn %O A267387 0,3 %A A267387 _Alois P. Heinz_, Jan 13 2016