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 A030269 #6 Dec 19 2015 12:30:39 %S A030269 0,0,1,2,6,18,69,287,1397,7634,46972,321014,2416305,19840547, %T A030269 176267022,1681915809,17127587977,185127766583 %N A030269 Number of nonisomorphic disconnected partial lattices. %C A030269 A partial lattice is a poset where every pair of points has a unique least upper (greatest lower) bound or has no upper (lower) bound. %Y A030269 a(n) = A006966(n-2) - A030268(n). %K A030269 nonn,hard %O A030269 0,4 %A A030269 _Christian G. Bower_, revised Dec 28 2000