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 A338584 #6 Dec 01 2020 17:10:26 %S A338584 1,6,28,128,558,2421,10675,47810,217572,1006211 %N A338584 Number of unlabeled nonplanar connected graphs with n edges with minimum degree 3 at each node that are not 3-connected. %H A338584 Hugo Pfoertner, <a href="/A338584/a338584.pdf">Illustration of terms a(13) and a(14)</a>. %F A338584 a(n) = A338593(n) - A338583(n). %Y A338584 Cf. A006290, A007112, A123545, A338583, A338593, A338594, A338604. %K A338584 nonn,more %O A338584 13,2 %A A338584 _Hugo Pfoertner_, Nov 21 2020