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 A210768 #18 Dec 02 2017 21:53:12 %S A210768 1,3,918,6669,33665,131616,425866,1192178,2977857 %N A210768 Number of bilaterally asymmetric 8-hoops with n symbols and no a-rooted trees. %C A210768 It appears that table 2 of the Williamson article contains typographical errors and the sequence was intended to read as in A210699. %H A210768 Williamson, S. G. <a href="http://dx.doi.org/10.1016/0012-365X(72)90043-X">The combinatorial analysis of patterns and the principle of inclusion-exclusion</a>. Discrete Math. 1 (1972), no. 4, 357--388. MR0299493 (45 #8541) %Y A210768 Cf. A210766, A060560, A295925. %K A210768 nonn %O A210768 2,2 %A A210768 _N. J. A. Sloane_, Mar 25 2012