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 A122671 #12 Feb 16 2023 14:45:48 %S A122671 1,3,15,62,312,1435,6785 %N A122671 Number of catacondensed coronoid systems with n hexagons with a single hole. %H A122671 S. J. Cyvin et al., <a href="https://doi.org/10.1007/BF00673438">The simplest coronoids: hollow hexagons</a>, Struct. Chem., 2 (1991), 555-566. %Y A122671 Cf. A038140. %K A122671 nonn,more %O A122671 8,2 %A A122671 _N. J. A. Sloane_, Sep 23 2006 %E A122671 Name clarified by _Andrey Zabolotskiy_, Feb 16 2023