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 A066305 #6 Mar 30 2012 17:37:12 %S A066305 1,0,2,5,22,117 %N A066305 Number of connected reduced partially ordered sets (posets) with n unlabeled elements. %H A066305 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a> %H A066305 <a href="/index/Pos#posets">Index entries for sequences related to posets</a> %Y A066305 Cf. A000608. Inverse Euler transform of A066304. %K A066305 nonn,more %O A066305 1,3 %A A066305 _Christian G. Bower_, Dec 12 2001