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 A121070 #3 Mar 30 2012 16:50:29 %S A121070 1,1,4,13,56,234,1034,4570,20492,92329,418896 %N A121070 Nonisomorphic catacondensed monoheptafusenes (see reference for precise definition). %D A121070 B. N. Cyvin et al., A class of polygonal systems representing polycyclic conjugated hydrocarbons ..., Monat. f. Chemie, 125 (1994), 1327-1337 (see Table 1). %Y A121070 Equals sum of columns of triangle whose successive columns are A000007, A044045, A121071, A045904, ... %K A121070 nonn %O A121070 0,3 %A A121070 _N. J. A. Sloane_, Aug 10 2006