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 A121332 #3 Mar 30 2012 16:50:30 %S A121332 0,1,5,20,71,235,753,2345,7190,21753,65188,193834,527743,1683615, %T A121332 4927394,14367845,41761634,121052806,350049108,1010123293,2909478000 %N A121332 Number of bridged bicyclic skeletons with n carbon atoms (see Parks et al. for precise definition). %D A121332 Camden A. Parks and James B. Hendrickson, Enumeration of monocyclic and bicyclic carbon skeletons, J. Chem. Inf. Comput. Sci., vol. 31, 334-339 (1991). %K A121332 nonn %O A121332 5,3 %A A121332 _N. J. A. Sloane_, Aug 27 2006