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 A338593 #11 Mar 07 2021 17:47:03 %S A338593 1,2,3,10,30,100,371,1419,5764,24482,107583,487647,2271488,10847623 %N A338593 Number of unlabeled connected nonplanar graphs with n edges with degree >= 3 at each node. %C A338593 First differs from A338583 for n = 13. All unlabeled nonplanar graphs with n <= 12 edges and degree >= 3 at each node are 3-connected. For this reason the illustrations of the graphs are identical up to n = 12. The first differences for n = 13 and n = 14 are shown in the illustrations of A338584. %H A338593 Hugo Pfoertner, <a href="/A338583/a338583.pdf">Illustrations of terms a(9) - a(12)</a>, from A338583. %H A338593 Hugo Pfoertner, <a href="/A338584/a338584.pdf">Illustration of terms a(13) and a(14)</a>, showing graphs counted in this sequence, but not in A338583 (illustrations from A338584). %H A338593 Hugo Pfoertner, <a href="http://www.randomwalk.de/sequences/a338593_d3np.zip">Unlabeled nonplanar graphs with vertex degree >=3 for n<=19 edges</a>, list in PARI-readable format. %F A338593 a(n) = A338604(n) - A338594(n). %o A338593 (PARI) \\ It is assumed that the a338593.gp file (from the linked zip archive) has been read before, i.e., \r [path]a338593.gp %o A338593 for(k=9,#EdgeDataNonplanarDegge3,print1(#EdgeDataNonplanarDegge3[k],", ")); %o A338593 \\ printing of the edge lists of the graphs for n <= 11 %o A338593 print(EdgeDataNonplanarDegge3[9..11]) %Y A338593 Cf. A007112, A002840, A123545, A338511, A338583, A338584, A338594, A338604. %K A338593 nonn,more %O A338593 9,2 %A A338593 _Hugo Pfoertner_, Nov 21 2020